[PATCH 1/9] Fix git patch header processing in git-apply.

[PATCH 1/9] Fix git patch header processing in git-apply.

[Robert Fitzsimons]

Stop processing and return NULL if we encounter a '\n' character
before we have two matching names in the git header.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 apply.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

289e53f770e37dfe25c740788256d24c19c2e16d
diff --git a/apply.c b/apply.c
--- a/apply.c
+++ b/apply.c
@@ -387,7 +387,7 @@ static char *git_header_name(char *line)
 		default:
 			continue;
 		case '\n':
-			break;
+			return NULL;
 		case '\t': case ' ':
 			second = name+len;
 			for (;;) {

[PATCH 2/9] Fix detection of files with only one line in git-apply.

[Robert Fitzsimons]

A patch which added one line to an empty file or removed the only line
from a one line file would be incorrectly detected as an invalid new
or delete patch.  Added a new test case.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 apply.c                  |    4 ++--
 t/t4103-apply-oneline.sh |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 t/t4103-apply-oneline.sh

babd40afef54b06775b11a877b347685edbedcd2
diff --git a/apply.c b/apply.c
--- a/apply.c
+++ b/apply.c
@@ -638,9 +638,9 @@ static int parse_fragment(char *line, un
 			patch->new_name = NULL;
 	}
 
-	if (patch->is_new != !oldlines)
+	if (patch->is_new && (patch->is_new != !oldlines))
 		return error("new file depends on old contents");
-	if (patch->is_delete != !newlines) {
+	if (patch->is_delete && (patch->is_delete != !newlines)) {
 		if (newlines)
 			return error("deleted file still has contents");
 		fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
diff --git a/t/t4103-apply-oneline.sh b/t/t4103-apply-oneline.sh
new file mode 100644
--- /dev/null
+++ b/t/t4103-apply-oneline.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply files with one line.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > patch1.patch <<\EOF
+diff --git a/main.c b/main.c
+new file mode 100644
+--- /dev/null
++++ b/main.c
+@@ -0,0 +0,0 @@
+EOF
+cat > patch2.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -0,0 +1,1 @@
++#include <stdio.h>
+EOF
+cat > patch3.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -1,1 +0,0 @@
+-#include <stdio.h>
+EOF
+
+test_expect_success "S = patch1 (new file with no lines)" \
+    'git-apply patch1.patch'
+
+test_expect_success "S = patch2 (add one line)" \
+    'git-apply patch2.patch'
+
+test_expect_success "S = patch3 (delete one line)" \
+    'git-apply patch3.patch'
+
+test_done
+

[PATCH 3/9] Fix processing of a patch file which modifies the same file in git-apply.

[Robert Fitzsimons]

A patch file (or stdin) which modifies the same file more then once
will fail to apply the patch correctly.  In the worst case it will
apply some of the patch and leave an invalid output file(s).

apply.c has been changed to search for previously processed files and
use the in memory copy of the data instead of the on disk image.
Added a series of test cases for the processing of complex single
file patches.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 apply.c                  |   64 +++++++++++++-
 t/t4104-apply-complex.sh |  211 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 270 insertions(+), 5 deletions(-)
 create mode 100644 t/t4104-apply-complex.sh

be1277e3531a03441839fd1dc750dad640ebf218
diff --git a/apply.c b/apply.c
--- a/apply.c
+++ b/apply.c
@@ -67,6 +67,7 @@ struct patch {
 	char *result;
 	unsigned long resultsize;
 	struct patch *next;
+	struct patch *prev;
 };
 
 #define CHUNKSIZE (8192)
@@ -974,7 +975,7 @@ static int apply_fragments(struct buffer
 	return 0;
 }
 
-static int apply_data(struct patch *patch, struct stat *st)
+static int apply_data(struct patch *patch, struct patch *old_patch, struct stat *st)
 {
 	char *buf;
 	unsigned long size, alloc;
@@ -983,7 +984,13 @@ static int apply_data(struct patch *patc
 	size = 0;
 	alloc = 0;
 	buf = NULL;
-	if (patch->old_name) {
+
+	if (patch->old_name && old_patch) {
+		size = old_patch->resultsize;
+		alloc = size + 8192;
+		buf = xmalloc(alloc);
+		memcpy(buf, old_patch->result, size);
+	} else if (patch->old_name) {
 		size = st->st_size;
 		alloc = size + 8192;
 		buf = xmalloc(alloc);
@@ -1010,8 +1017,46 @@ static int check_patch(struct patch *pat
 	struct stat st;
 	const char *old_name = patch->old_name;
 	const char *new_name = patch->new_name;
+	struct patch *old_patch = NULL;
+	struct patch *new_patch = NULL;
 
 	if (old_name) {
+		for (old_patch = patch->prev; old_patch; old_patch = old_patch->prev) {
+			if (old_patch->new_name && !strcmp(old_name, old_patch->new_name)) {
+				break;
+			}
+			if (old_patch->old_name && !strcmp(old_name, old_patch->old_name)) {
+				if (old_patch->is_delete || old_patch->is_rename) {
+					return error("%s: file missing because of previous patch", old_name);
+				}
+				break;
+			}
+		}
+	}
+
+	if (new_name) {
+		for (new_patch = patch->prev; new_patch; new_patch = new_patch->prev) {
+			if (new_patch->new_name && !strcmp(new_name, new_patch->new_name)) {
+				if (patch->is_new || patch->is_rename || patch->is_copy)
+					return error("%s: file exists from previous patch (new)", new_name);
+				break;
+			}
+			if (new_patch->old_name && !strcmp(new_name, new_patch->old_name)) {
+				if (!(patch->is_new || patch->is_delete || patch->is_rename || patch->is_copy))
+					break;
+				if (new_patch->is_delete || new_patch->is_rename)
+					break;
+				return error("%s: file exists from previous patch (old)", new_name);
+			}
+		}
+	}
+
+	if (old_patch) {
+		if (patch->is_new < 0)
+			patch->is_new = 0;
+		if (!patch->old_mode)
+			patch->old_mode = old_patch->new_mode;
+	} else if (old_name) {
 		int changed;
 
 		if (lstat(old_name, &st) < 0)
@@ -1036,7 +1081,14 @@ static int check_patch(struct patch *pat
 				old_name, st.st_mode, patch->old_mode);
 	}
 
-	if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
+	if (new_patch) {
+		if (!patch->new_mode) {
+			if (patch->is_new)
+				patch->new_mode = S_IFREG | 0644;
+			else
+				patch->new_mode = patch->old_mode;
+		}
+	} else if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
 		if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
 			return error("%s: already exists in index", new_name);
 		if (!lstat(new_name, &st))
@@ -1061,7 +1113,7 @@ static int check_patch(struct patch *pat
 				same ? "" : " of ", same ? "" : old_name);
 	}	
 
-	if (apply_data(patch, &st) < 0)
+	if (apply_data(patch, old_patch, &st) < 0)
 		return error("%s: patch does not apply", old_name);
 	return 0;
 }
@@ -1393,6 +1445,7 @@ static int apply_patch(int fd)
 	unsigned long offset, size;
 	char *buffer = read_patch_file(fd, &size);
 	struct patch *list = NULL, **listp = &list;
+	struct patch *list_prev = NULL;
 	int skipped_patch = 0;
 
 	if (!buffer)
@@ -1409,7 +1462,8 @@ static int apply_patch(int fd)
 			break;
 		if (use_patch(patch)) {
 			patch_stats(patch);
-			*listp = patch;
+			patch->prev = list_prev;
+			list_prev = *listp = patch;
 			listp = &patch->next;
 		} else {
 			/* perhaps free it a bit better? */
diff --git a/t/t4104-apply-complex.sh b/t/t4104-apply-complex.sh
new file mode 100644
--- /dev/null
+++ b/t/t4104-apply-complex.sh
@@ -0,0 +1,211 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply complex patches.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > Nx <<\EOF
+diff --git a/x.txt b/x.txt
+new file mode 100644
+--- /dev/null
++++ b/x.txt
+EOF
+cat > Ny <<\EOF
+diff --git a/y.txt b/y.txt
+new file mode 100644
+--- /dev/null
++++ b/y.txt
+EOF
+cat > Rxy <<\EOF
+diff --git a/x.txt b/y.txt
+rename from x.txt
+rename to y.txt
+--- a/x.txt
++++ b/y.txt
+EOF
+cat > Ryx <<\EOF
+diff --git a/y.txt b/x.txt
+rename from y.txt
+rename to x.txt
+--- a/y.txt
++++ b/x.txt
+EOF
+cat > Cxy <<\EOF
+diff --git a/x.txt b/y.txt
+copy from x.txt
+copy to y.txt
+--- a/x.txt
++++ b/y.txt
+EOF
+cat > Cyx <<\EOF
+diff --git a/y.txt b/x.txt
+copy from y.txt
+copy to x.txt
+--- a/y.txt
++++ b/x.txt
+EOF
+cat > Dx <<\EOF
+diff --git a/x.txt b/x.txt
+deleted file mode 100644
+--- a/x.txt
++++ /dev/null
+EOF
+cat > Dy <<\EOF
+diff --git a/y.txt b/y.txt
+deleted file mode 100644
+--- a/y.txt
++++ /dev/null
+EOF
+cat > Px1 <<\EOF
+diff --git a/x.txt b/x.txt
+--- a/x.txt
++++ b/x.txt
+@@ -0,0 +1 @@
++XXX
+EOF
+cat > Px2 <<\EOF
+diff --git a/x.txt b/x.txt
+--- a/x.txt
++++ b/x.txt
+@@ -1 +1,2 @@
+ XXX
++XX
+EOF
+cat > Px3 <<\EOF
+diff --git a/x.txt b/x.txt
+--- a/x.txt
++++ b/x.txt
+@@ -1,2 +0,0 @@
+-XXX
+-XX
+EOF
+
+test_expect_success "S = Nx Cxy Dx Dy Ny Ryx Cxy Dx Dy (files)" \
+    'git-apply Nx Cxy Dx Dy Ny Ryx Cxy Dx Dy'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Cxy Dx Dy Ny Ryx Cxy Dx Dy (stdin)" \
+    'cat Nx Cxy Dx Dy Ny Ryx Cxy Dx Dy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx" \
+    'cat Nx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Dx" \
+    'cat Nx Dx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Px1" \
+    'cat Nx Px1 | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Px1 Px2" \
+    'cat Nx Px1 Px2 | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Px1 Px2 Px3" \
+    'cat Nx Px1 Px2 Px3 | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Px1 Px2 Px3 Dx" \
+    'cat Nx Px1 Px2 Px3 Dx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Rxy" \
+    'cat Nx Rxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Rxy Dy" \
+    'cat Nx Rxy Dy| git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Cxy" \
+    'cat Nx Cxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Rxy Dx Dy" \
+    'cat Nx Cxy Dx Dy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Ny Ryx Px1 Px2 Cxy Px3 Dx" \
+    'cat Ny Ryx Px1 Px2 Cxy Px3 Dx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Ny Ryx Px1 Px2 Cxy Px3 Dx Cyx" \
+    'cat Ny Ryx Px1 Px2 Cxy Px3 Dx Cyx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Ny Cyx Px1 Px2 Px3 Dy Cxy Dx Cyx Dy Rxy Dy" \
+    'cat Ny Cyx Px1 Px2 Px3 Dy Cxy Dx Cyx Dy Rxy Dy| git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Dx" \
+    'cat Dx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Rxy" \
+    'cat Rxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Cxy" \
+    'cat Cxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Nx Dx Dx" \
+    'cat Nx Dx Dx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Nx Ny Rxy" \
+    'cat Nx Ny Rxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Ny Rxy" \
+    'cat Ny Rxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Nx Ny Cxy" \
+    'cat Nx Ny Cxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Ny Cxy" \
+    'cat Ny Cxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Nx Cxy Cxy" \
+    'cat Nx Cxy Cxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Nx Cxy Cyx" \
+    'cat Nx Cxy Cyx | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Nx Rxy Rxy" \
+    'cat Nx Rxy Rxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Nx Rxy Cxy" \
+    'cat Nx Rxy Cxy | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_failure "F = Ny Ryx Px1 Px2 Px3 Dx Cyx Px2" \
+    'cat Ny Ryx Px1 Px2 Px3 Dx Cyx Px2 | git-apply -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Cxy Dx Cyx Dy Rxy Dy Nx Ny Dx Ryx Cxy Dx Dy Nx Rxy Dy Nx Cxy Dy Dx (--check)" \
+    'cat Nx Cxy Dx Cyx Dy Rxy Dy Nx Ny Dx Ryx Cxy Dx Dy Nx Rxy Dy Nx Cxy Dy Dx | git-apply --check -'
+rm -f x.txt y.txt
+
+test_expect_success "S = Nx Cxy Dx Cyx Dy Rxy Dy Nx Ny Dx Ryx Cxy Dx Dy Nx Rxy Dy Nx Cxy Dy Dx" \
+    'cat Nx Cxy Dx Cyx Dy Rxy Dy Nx Ny Dx Ryx Cxy Dx Dy Nx Rxy Dy Nx Cxy Dy Dx | git-apply -'
+rm -f x.txt y.txt
+
+test_done
+

[PATCH 4/9] Fix the procssing of multiple patch files with --check in git-apply.

[Robert Fitzsimons]

When the --check option was used with multiple patch files which
modify the same files, the patch can fail because the previously
modified contents aren't written to the disk.

So save the in memory patch contents across the processing of multiple
patch files.  Added a new test case for --check with multiple patch
files.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 apply.c                |   10 ++++-
 t/t4105-apply-check.sh |   89 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+), 2 deletions(-)
 create mode 100644 t/t4105-apply-check.sh

80ed0622e31bd52cedd073f54c9a9364b5289c89
diff --git a/apply.c b/apply.c
--- a/apply.c
+++ b/apply.c
@@ -1439,13 +1439,16 @@ static int use_patch(struct patch *p)
 	return 1;
 }
 
+struct patch *master_list = NULL;
+struct patch *master_list_prev = NULL;
+
 static int apply_patch(int fd)
 {
 	int newfd;
 	unsigned long offset, size;
 	char *buffer = read_patch_file(fd, &size);
-	struct patch *list = NULL, **listp = &list;
-	struct patch *list_prev = NULL;
+	struct patch *list = master_list, **listp = &list;
+	struct patch *list_prev = master_list_prev;
 	int skipped_patch = 0;
 
 	if (!buffer)
@@ -1504,6 +1507,9 @@ static int apply_patch(int fd)
 	if (summary)
 		summary_patch_list(list);
 
+	master_list = list;
+	master_list_prev = list_prev;
+
 	free(buffer);
 	return 0;
 }
diff --git a/t/t4105-apply-check.sh b/t/t4105-apply-check.sh
new file mode 100644
--- /dev/null
+++ b/t/t4105-apply-check.sh
@@ -0,0 +1,89 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply --check with multiple files.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > patch1.patch <<\EOF
+diff --git a/main.c b/main.c
+new file mode 100644
+--- /dev/null
++++ b/main.c
+@@ -0,0 +1,23 @@
++#include <stdio.h>
++
++void print_int(int num);
++int func(int num);
++
++int main() {
++	int i;
++
++	for (i = 0; i < 10; i++) {
++		print_int(func(i));
++	}
++
++	return 0;
++}
++
++int func(int num) {
++	return num * num;
++}
++
++void print_int(int num) {
++	printf("%d", num);
++}
++
+EOF
+cat > patch2.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -10,6 +10,8 @@
+ 		print_int(func(i));
+ 	}
+ 
++	printf("\n");
++
+ 	return 0;
+ }
+ 
+EOF
+cat > patch3.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -18,6 +20,6 @@
+ }
+ 
+ void print_int(int num) {
+-	printf("%d", num);
++	printf("%d ", num);
+ }
+ 
+EOF
+
+test_expect_success "S = test 1" \
+    'git-apply patch1.patch patch2.patch patch3.patch'
+rm -f main.c
+
+test_expect_success "S = test 2" \
+    'git-apply --check patch1.patch patch2.patch patch3.patch'
+rm -f main.c
+
+test_expect_success "S = test 3" \
+    'cat patch1.patch patch2.patch patch3.patch | git-apply'
+rm -f main.c
+
+test_expect_success "S = test 4" \
+    'cat patch1.patch patch2.patch patch3.patch | git-apply --check'
+rm -f main.c
+
+test_done
+

[PATCH 5/9] New option --force-delete for git-apply.

[Robert Fitzsimons]

Allow the user to force a patch that deletes a file to succeed even
though the file might still contain data.  Added a test case.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 Documentation/git-apply.txt  |    8 +++++-
 apply.c                      |   12 ++++++++-
 t/t4106-apply-force-delete.h |   54 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+), 3 deletions(-)
 create mode 100644 t/t4106-apply-force-delete.h

3fb13d4a86a1af7b545ce5f99904c1a5adae27e7
diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
--- a/Documentation/git-apply.txt
+++ b/Documentation/git-apply.txt
@@ -9,7 +9,9 @@ git-apply - Apply patch on a GIT index f
 
 SYNOPSIS
 --------
-'git-apply' [--no-merge] [--stat] [--summary] [--check] [--index] [--show-files] [--apply] [<patch>...]
+'git-apply' [--no-merge] [--stat] [--summary] [--check]
+		[--index] [--show-files] [--apply]
+		[--force-delete] [<patch>...]
 
 DESCRIPTION
 -----------
@@ -61,6 +63,10 @@ OPTIONS
 	patch.  Give this flag after those flags to also apply
 	the patch.
 
+--force-delete::
+	Force a patch which deletes a file to succeed even if
+	file contents would be left behind, lines added or the
+	patch will not apply.
 
 Author
 ------
diff --git a/apply.c b/apply.c
--- a/apply.c
+++ b/apply.c
@@ -32,8 +32,9 @@ static int summary = 0;
 static int check = 0;
 static int apply = 1;
 static int show_files = 0;
+static int force_delete = 0;
 static const char apply_usage[] =
-"git-apply [--no-merge] [--stat] [--summary] [--check] [--index] [--apply] [--show-files] <patch>...";
+"git-apply [--no-merge] [--stat] [--summary] [--check] [--index] [--apply] [--show-files] [--force-delete] <patch>...";
 
 /*
  * For "diff-stat" like behaviour, we keep track of the biggest change
@@ -641,7 +642,7 @@ static int parse_fragment(char *line, un
 
 	if (patch->is_new && (patch->is_new != !oldlines))
 		return error("new file depends on old contents");
-	if (patch->is_delete && (patch->is_delete != !newlines)) {
+	if (!force_delete && patch->is_delete && (patch->is_delete != !newlines)) {
 		if (newlines)
 			return error("deleted file still has contents");
 		fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
@@ -981,6 +982,9 @@ static int apply_data(struct patch *patc
 	unsigned long size, alloc;
 	struct buffer_desc desc;
 
+	if (force_delete && patch->is_delete)
+		return 0;
+
 	size = 0;
 	alloc = 0;
 	buf = NULL;
@@ -1567,6 +1571,10 @@ int main(int argc, char **argv)
 			show_files = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--force-delete")) {
+			force_delete = 1;
+			continue;
+		}
 		fd = open(arg, O_RDONLY);
 		if (fd < 0)
 			usage(apply_usage);
diff --git a/t/t4106-apply-force-delete.h b/t/t4106-apply-force-delete.h
new file mode 100644
--- /dev/null
+++ b/t/t4106-apply-force-delete.h
@@ -0,0 +1,54 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply --force-delete.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > patch1.patch <<\EOF
+diff --git a/main.c b/main.c
+new file mode 100644
+--- /dev/null
++++ b/main.c
+@@ -0,0 +1,3 @@
++int main() {
++       return 0;
++}
+EOF
+cat > patch2.patch <<\EOF
+diff --git a/main.c b/main.c
+deleted file mode 100644
+--- a/main.c
++++ /dev/null
+@@ -1,3 +0,0 @@
+-int main() {
+-       return 0;
+-}
+EOF
+cat > patch3.patch <<\EOF
+diff --git a/main.c b/main.c
+deleted file mode 100644
+--- a/main.c
++++ /dev/null
+EOF
+
+test_expect_success "S = new, del" \
+    'git-apply patch1.patch patch2.patch'
+rm -f main.c
+
+test_expect_failure "F = new, del short" \
+    'git-apply patch1.patch patch3.patch'
+rm -f main.c
+
+test_expect_success "S = new, del short (--force-delete)" \
+    'git-apply --force-delete patch1.patch patch3.patch'
+rm -f main.c
+
+test_done
+

[PATCH 6/9] New option --ignore-whitespace for git-apply.

[Robert Fitzsimons]

Allow the user to force a patch to be applied even though there might
be whitespace differences.  Added a test case for the new option.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 Documentation/git-apply.txt        |    7 +++-
 apply.c                            |   38 ++++++++++++++++++-
 t/t4107-apply-ignore-whitespace.sh |   72 ++++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+), 4 deletions(-)
 create mode 100644 t/t4107-apply-ignore-whitespace.sh

a928441d83ccc347b1d57fc561d413da56b93197
diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
--- a/Documentation/git-apply.txt
+++ b/Documentation/git-apply.txt
@@ -11,7 +11,8 @@ SYNOPSIS
 --------
 'git-apply' [--no-merge] [--stat] [--summary] [--check]
 		[--index] [--show-files] [--apply]
-		[--force-delete] [<patch>...]
+		[--force-delete] [--ignore-whitespace]
+		[<patch>...]
 
 DESCRIPTION
 -----------
@@ -68,6 +69,10 @@ OPTIONS
 	file contents would be left behind, lines added or the
 	patch will not apply.
 
+--ignore-whitespace::
+	When matching the patch to the file contents ignore
+	sequences of tabs or spaces.
+
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org>
diff --git a/apply.c b/apply.c
--- a/apply.c
+++ b/apply.c
@@ -33,8 +33,9 @@ static int check = 0;
 static int apply = 1;
 static int show_files = 0;
 static int force_delete = 0;
+static int ignore_whitespace = 0;
 static const char apply_usage[] =
-"git-apply [--no-merge] [--stat] [--summary] [--check] [--index] [--apply] [--show-files] [--force-delete] <patch>...";
+"git-apply [--no-merge] [--stat] [--summary] [--check] [--index] [--apply] [--show-files] [--force-delete] [--ignore-whitespace] <patch>...";
 
 /*
  * For "diff-stat" like behaviour, we keep track of the biggest change
@@ -109,6 +110,27 @@ static void *read_patch_file(int fd, uns
 	return buffer;
 }
 
+static int memcmp_ignore_whitespace(const char *s1, const char *s2, size_t n)
+{
+	const char *stop = s1 + n;
+	int result;
+
+	if (!n)
+		return 0;
+
+	do {
+		if (((*s1 == ' ') || (*s1 == '\t')) && ((*s2 == ' ') || (*s2 == '\t'))) {
+			while ((*s1 == ' ') || (*s1 == '\t'))
+				s1++;
+			while ((*s2 == ' ') || (*s2 == '\t'))
+				s2++;
+		}
+		result = *s1++ - *s2++;
+	} while (!result && (s1 < stop));
+
+	return result;
+}
+
 static unsigned long linelen(const char *buffer, unsigned long size)
 {
 	unsigned long len = 0;
@@ -839,7 +861,10 @@ static int find_offset(const char *buf, 
 	}
 
 	/* Exact line number? */
-	if (!memcmp(buf + start, fragment, fragsize))
+	if (ignore_whitespace) {
+		if (!memcmp_ignore_whitespace(buf + start, fragment, fragsize))
+			return start;
+	} else if (!memcmp(buf + start, fragment, fragsize))
 		return start;
 
 	/*
@@ -873,7 +898,10 @@ static int find_offset(const char *buf, 
 
 		if (try + fragsize > size)
 			continue;
-		if (memcmp(buf + try, fragment, fragsize))
+		if (ignore_whitespace) {
+			if (memcmp_ignore_whitespace(buf + try, fragment, fragsize))
+				continue;
+		} else if (memcmp(buf + try, fragment, fragsize))
 			continue;
 		n = (i >> 1)+1;
 		if (i & 1)
@@ -1575,6 +1603,10 @@ int main(int argc, char **argv)
 			force_delete = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--ignore-whitespace")) {
+			ignore_whitespace = 1;
+			continue;
+		}
 		fd = open(arg, O_RDONLY);
 		if (fd < 0)
 			usage(apply_usage);
diff --git a/t/t4107-apply-ignore-whitespace.sh b/t/t4107-apply-ignore-whitespace.sh
new file mode 100644
--- /dev/null
+++ b/t/t4107-apply-ignore-whitespace.sh
@@ -0,0 +1,72 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply --ignore-whitespace.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > patch1.patch <<\EOF
+diff --git a/main.c b/main.c
+new file mode 100644
+--- /dev/null
++++ b/main.c
+@@ -0,0 +1,23 @@
++#include <stdio.h>
++
++void print_int(int num);
++int func(int num);
++
++int main() {
++       int i;
++
++       for (i = 0; i < 10; i++) {
++               print_int(func(i));
++       }
++
++       return 0;
++}
++
++int func(int num) {
++       return num * num;
++}
++
++void print_int(int num) {
++       printf("%d", num);
++}
++
+EOF
+cat > patch2.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -10,6 +10,8 @@
+ 		print_int(func(i));
+ 	}
+ 
++	printf("\n");
++
+ 	return 0;
+ }
+EOF
+
+test_expect_success "S = patch1" \
+    'git-apply patch1.patch'
+
+test_expect_failure "F = patch2" \
+    'git-apply patch2.patch'
+
+test_expect_success "S = patch2 (--ignore-whitespace)" \
+    'git-apply --ignore-whitespace patch2.patch'
+
+rm -f main.c
+test_expect_success "S = patch1 (--ignore-whitespace)" \
+    'git-apply --ignore-whitespace patch1.patch'
+
+test_done
+

[PATCH 7/9] New option --ignore-applied for git-apply.

[Robert Fitzsimons]

Allow the user to allow a patch which has some hunks (fragments)
already applied to succeed.  Added test case and documentation.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 Documentation/git-apply.txt     |    6 ++
 apply.c                         |   12 +++++
 t/t4108-apply-ignore-applied.sh |   94 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+), 2 deletions(-)
 create mode 100644 t/t4108-apply-ignore-applied.sh

5e36f3b7c8ca0710096552ce3f20f16da04e601b
diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
--- a/Documentation/git-apply.txt
+++ b/Documentation/git-apply.txt
@@ -12,7 +12,7 @@ SYNOPSIS
 'git-apply' [--no-merge] [--stat] [--summary] [--check]
 		[--index] [--show-files] [--apply]
 		[--force-delete] [--ignore-whitespace]
-		[<patch>...]
+		[--ignore-applied] [<patch>...]
 
 DESCRIPTION
 -----------
@@ -73,6 +73,10 @@ OPTIONS
 	When matching the patch to the file contents ignore
 	sequences of tabs or spaces.
 
+--ignore-applied::
+	If a patch hunk (fragment) fails to apply, reverse the
+	hunk and check if the hunk has already been applied.
+
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org>
diff --git a/apply.c b/apply.c
--- a/apply.c
+++ b/apply.c
@@ -34,8 +34,9 @@ static int apply = 1;
 static int show_files = 0;
 static int force_delete = 0;
 static int ignore_whitespace = 0;
+static int ignore_applied = 0;
 static const char apply_usage[] =
-"git-apply [--no-merge] [--stat] [--summary] [--check] [--index] [--apply] [--show-files] [--force-delete] [--ignore-whitespace] <patch>...";
+"git-apply [--no-merge] [--stat] [--summary] [--check] [--index] [--apply] [--show-files] [--force-delete] [--ignore-whitespace] [--ignore-applied] <patch>...";
 
 /*
  * For "diff-stat" like behaviour, we keep track of the biggest change
@@ -985,6 +986,11 @@ static int apply_one_fragment(struct buf
 		memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
 		memcpy(buf + offset, new, newsize);
 		offset = 0;
+	} else if (ignore_applied) {
+		offset = find_offset(buf, desc->size, new, newsize, frag->newpos);
+		if (offset >= 0) {
+			offset = 0;
+		}
 	}
 
 	free(old);
@@ -1607,6 +1613,10 @@ int main(int argc, char **argv)
 			ignore_whitespace = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--ignore-applied")) {
+			ignore_applied = 1;
+			continue;
+		}
 		fd = open(arg, O_RDONLY);
 		if (fd < 0)
 			usage(apply_usage);
diff --git a/t/t4108-apply-ignore-applied.sh b/t/t4108-apply-ignore-applied.sh
new file mode 100644
--- /dev/null
+++ b/t/t4108-apply-ignore-applied.sh
@@ -0,0 +1,94 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply --ignore-applied.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > patch1.patch <<\EOF
+diff --git a/main.c b/main.c
+new file mode 100644
+--- /dev/null
++++ b/main.c
+@@ -0,0 +1,23 @@
++#include <stdio.h>
++
++void print_int(int num);
++int func(int num);
++
++int main() {
++	int i;
++
++	for (i = 0; i < 10; i++) {
++		print_int(func(i));
++	}
++
++	return 0;
++}
++
++int func(int num) {
++	return num * num;
++}
++
++void print_int(int num) {
++	printf("%d", num);
++}
++
+EOF
+cat > patch2.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -10,6 +10,8 @@
+ 		print_int(func(i));
+ 	}
+ 
++	printf("\n");
++
+ 	return 0;
+ }
+ 
+EOF
+cat > patch3.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -10,6 +10,8 @@
+ 		print_int(func(i));
+ 	}
+ 
++	printf("\n");
++
+ 	return 0;
+ }
+ 
+@@ -18,6 +20,6 @@
+ }
+ 
+ void print_int(int num) {
+-	printf("%d", num);
++	printf("%d ", num);
+ }
+ 
+EOF
+
+test_expect_failure "F = test 1" \
+    'cat patch1.patch patch2.patch patch2.patch | git-apply --check'
+
+test_expect_success "S = test 2" \
+    'cat patch1.patch patch2.patch patch2.patch | git-apply --check --ignore-applied'
+
+test_expect_failure "F = test 3" \
+    'cat patch1.patch patch3.patch patch3.patch | git-apply --check'
+
+test_expect_success "S = test 4" \
+    'cat patch1.patch patch2.patch patch3.patch | git-apply --check --ignore-applied'
+
+test_done
+

[PATCH 8/9] New git-apply test cases for patches with mulitple fragments.

[Robert Fitzsimons]

Added a test case for patches with multiple fragments.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 t/t4109-apply-multifrag.sh |  176 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 176 insertions(+), 0 deletions(-)
 create mode 100644 t/t4109-apply-multifrag.sh

28b46271270ad79ba8720a3fde1f40724493fdfe
diff --git a/t/t4109-apply-multifrag.sh b/t/t4109-apply-multifrag.sh
new file mode 100644
--- /dev/null
+++ b/t/t4109-apply-multifrag.sh
@@ -0,0 +1,176 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply test patches with multiple fragments.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > patch1.patch <<\EOF
+diff --git a/main.c b/main.c
+new file mode 100644
+--- /dev/null
++++ b/main.c
+@@ -0,0 +1,23 @@
++#include <stdio.h>
++
++int func(int num);
++void print_int(int num);
++
++int main() {
++	int i;
++
++	for (i = 0; i < 10; i++) {
++		print_int(func(i));
++	}
++
++	return 0;
++}
++
++int func(int num) {
++	return num * num;
++}
++
++void print_int(int num) {
++	printf("%d", num);
++}
++
+EOF
+cat > patch2.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -1,7 +1,9 @@
++#include <stdlib.h>
+ #include <stdio.h>
+ 
+ int func(int num);
+ void print_int(int num);
++void print_ln();
+ 
+ int main() {
+ 	int i;
+@@ -10,6 +12,8 @@
+ 		print_int(func(i));
+ 	}
+ 
++	print_ln();
++
+ 	return 0;
+ }
+ 
+@@ -21,3 +25,7 @@
+ 	printf("%d", num);
+ }
+ 
++void print_ln() {
++	printf("\n");
++}
++
+EOF
+cat > patch3.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -1,9 +1,7 @@
+-#include <stdlib.h>
+ #include <stdio.h>
+ 
+ int func(int num);
+ void print_int(int num);
+-void print_ln();
+ 
+ int main() {
+ 	int i;
+@@ -12,8 +10,6 @@
+ 		print_int(func(i));
+ 	}
+ 
+-	print_ln();
+-
+ 	return 0;
+ }
+ 
+@@ -25,7 +21,3 @@
+ 	printf("%d", num);
+ }
+ 
+-void print_ln() {
+-	printf("\n");
+-}
+-
+EOF
+cat > patch4.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -1,13 +1,14 @@
+ #include <stdio.h>
+ 
+ int func(int num);
+-void print_int(int num);
++int func2(int num);
+ 
+ int main() {
+ 	int i;
+ 
+ 	for (i = 0; i < 10; i++) {
+-		print_int(func(i));
++		printf("%d", func(i));
++		printf("%d", func3(i));
+ 	}
+ 
+ 	return 0;
+@@ -17,7 +18,7 @@
+ 	return num * num;
+ }
+ 
+-void print_int(int num) {
+-	printf("%d", num);
++int func2(int num) {
++	return num * num * num;
+ }
+ 
+EOF
+
+test_expect_success "S = git-apply (1)" \
+    'git-apply patch1.patch patch2.patch'
+mv main.c main.c.git
+
+test_expect_success "S = patch (1)" \
+    'cat patch1.patch patch2.patch | patch -p1'
+
+test_expect_success "S = cmp (1)" \
+    'cmp main.c.git main.c'
+
+rm -f main.c main.c.git
+
+test_expect_success "S = git-apply (2)" \
+    'git-apply patch1.patch patch2.patch patch3.patch'
+mv main.c main.c.git
+
+test_expect_success "S = patch (2)" \
+    'cat patch1.patch patch2.patch patch3.patch | patch -p1'
+
+test_expect_success "S = cmp (2)" \
+    'cmp main.c.git main.c'
+
+rm -f main.c main.c.git
+
+test_expect_success "S = git-apply (3)" \
+    'git-apply patch1.patch patch4.patch'
+mv main.c main.c.git
+
+test_expect_success "S = patch (3)" \
+    'cat patch1.patch patch4.patch | patch -p1'
+
+test_expect_success "S = cmp (3)" \
+    'cmp main.c.git main.c'
+
+test_done
+

[PATCH 9/9] New git-apply test cases for scanning forwards and backwards.

[Robert Fitzsimons]

Added a new test case for the scanning forwards and backwards for the
correct location to apply a patch fragment.

Signed-off-by: Robert Fitzsimons <robfitz@273k.net>

---

 t/t4110-apply-scan.sh |  101 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 101 insertions(+), 0 deletions(-)
 create mode 100644 t/t4110-apply-scan.sh

51e9797ee16edc9d6164f2c7afaf1f8245538255
diff --git a/t/t4110-apply-scan.sh b/t/t4110-apply-scan.sh
new file mode 100644
--- /dev/null
+++ b/t/t4110-apply-scan.sh
@@ -0,0 +1,101 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+# Copyright (c) 2005 Robert Fitzsimons
+#
+
+test_description='git-apply test for patches which require scanning forwards and backwards.
+
+'
+. ./test-lib.sh
+
+# setup
+
+cat > patch1.patch <<\EOF
+diff --git a/new.txt b/new.txt
+new file mode 100644
+--- /dev/null
++++ b/new.txt
+@@ -0,0 +1,12 @@
++a1
++a11
++a111
++a1111
++b1
++b11
++b111
++b1111
++c1
++c11
++c111
++c1111
+EOF
+cat > patch2.patch <<\EOF
+diff --git a/new.txt b/new.txt
+--- a/new.txt
++++ b/new.txt
+@@ -1,7 +1,3 @@
+-a1
+-a11
+-a111
+-a1111
+ b1
+ b11
+ b111
+EOF
+cat > patch3.patch <<\EOF
+diff --git a/new.txt b/new.txt
+--- a/new.txt
++++ b/new.txt
+@@ -6,6 +6,10 @@
+ b11
+ b111
+ b1111
++b2
++b22
++b222
++b2222
+ c1
+ c11
+ c111
+EOF
+cat > patch4.patch <<\EOF
+diff --git a/new.txt b/new.txt
+--- a/new.txt
++++ b/new.txt
+@@ -1,3 +1,7 @@
++a1
++a11
++a111
++a1111
+ b1
+ b11
+ b111
+EOF
+cat > patch5.patch <<\EOF
+diff --git a/new.txt b/new.txt
+--- a/new.txt
++++ b/new.txt
+@@ -10,3 +10,7 @@
+ c11
+ c111
+ c1111
++c2
++c22
++c222
++c2222
+EOF
+
+test_expect_success "S = git-apply scan" \
+    'git-apply patch1.patch patch2.patch patch3.patch patch4.patch patch5.patch'
+mv new.txt apply.txt
+
+test_expect_success "S = patch scan" \
+    'cat patch1.patch patch2.patch patch3.patch patch4.patch patch5.patch | patch'
+mv new.txt patch.txt
+
+test_expect_success "S = cmp" \
+    'cmp apply.txt patch.txt'
+
+test_done
+

Re: [PATCH 6/9] New option --ignore-whitespace for git-apply.

[Linus Torvalds]

On Sun, 28 Aug 2005, Robert Fitzsimons wrote:
>
> Allow the user to force a patch to be applied even though there might
> be whitespace differences.  Added a test case for the new option.

If you ignore whitespace, then you should probably accept patches that are
whitespace corrupted in another way: lines missing the ' ' at the
beginning. Especially lines that are empty. That's actually the most 
common form of whitespace corruption there is.

		Linus

Re: [PATCH 6/9] New option --ignore-whitespace for git-apply.

[A Large Angry SCM]

Linus Torvalds wrote:
> On Sun, 28 Aug 2005, Robert Fitzsimons wrote:
>>Allow the user to force a patch to be applied even though there might
>>be whitespace differences.  Added a test case for the new option.
> 
> If you ignore whitespace, then you should probably accept patches that are
> whitespace corrupted in another way: lines missing the ' ' at the
> beginning. Especially lines that are empty. That's actually the most 
> common form of whitespace corruption there is.

Actually, a more restricted from of --ignore-whitespace may be useful, 
--ignore-trailing-whitespace (needs a shorter name!). Ignore only 
trailing whitespace differences (including empty context lines without 
the initial space).

Re: [PATCH 6/9] New option --ignore-whitespace for git-apply.

[Junio C Hamano]

Robert Fitzsimons <robfitz@273k.net> writes:

> Allow the user to force a patch to be applied even though there might
> be whitespace differences.  Added a test case for the new option.

It might be worth doing fuzz in general, but treating
whitespace-only fuzz specially is a good idea, since they are
usually more benign.

Re: [PATCH 5/9] New option --force-delete for git-apply.

[Junio C Hamano]

Robert Fitzsimons <robfitz@273k.net> writes:

> Allow the user to force a patch that deletes a file to succeed even
> though the file might still contain data.  Added a test case.

Why?

I've seen cases where git-apply incorrectly thinks a patch
leaves some data in a file to be deleted, when incomplete lines
are involved.  But I think that bug has been fixed, and the only
case where you would need this new flag should be dealing with a
corrupt/invalid patch.

Re: [PATCH 3/9] Fix processing of a patch file which modifies the same file in git-apply.

[Junio C Hamano]

Robert Fitzsimons <robfitz@273k.net> writes:

> A patch file (or stdin) which modifies the same file more then once
> will fail to apply the patch correctly.  In the worst case it will
> apply some of the patch and leave an invalid output file(s).

I am not sure if this is solving the right problem.  A patch
that touches the same file more than once is hard to review and
I think we should be discouraging the users to do so.  The same
comment goes for [PATCH 4/9].

Re: [PATCH 2/9] Fix detection of files with only one line in git-apply.

[Linus Torvalds]

On Sun, 28 Aug 2005, Robert Fitzsimons wrote:
>
> A patch which added one line to an empty file or removed the only line
> from a one line file would be incorrectly detected as an invalid new
> or delete patch.  Added a new test case.

This patch looks wrong or at least needs some more thought. The test was
done the way it was done for a reason. For example:

	if (patch->is_new != !oldlines)
		return error("new file depends on old contents");

actually has two error cases (admittedly it re-uses the same error message 
for both, which is a bit confusing):

 - is_new, and oldlines != 0

	This is the obvious error, and the one the message talk about.

 - !is_new, and oldlines == 0

	In kernel usage, empty files are not legal, and empty files get 
	deleted. So this actually was intentional, even if the error 
	message ends up being less than perfect.

The "is_delete" thing is the same. At least for the kernel, I want a patch 
that removes all content to also always _delete_ the file, because 
otherwise old-style patches are ambiguous. Is it a delete, or is it a 
"leave an empty file"?

Now, git patches aren't ambigious, so while git patches can clearly say 
"this is a patch to an existing empty file" vs "this patch creates this 
file", I wanted to have the behaviour where we maintain the principle that 
empty files are wrong.

Now, that's a kernel-specific thing, so it may be that enabling this
behaviour this should be a command line flag, but the point is that I 
don't want to entirely lose the test.

		Linus

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Junio C Hamano]

Thanks for "apply" patches.  I have merged some of them and
pushed out.

I further wanted to apply the following to the proposed updates
branch, but even with only the first one applied, it fails its
own test, t4104-apply-complex.sh:

* Fix processing of a patch file which modifies the same file in git-apply.
* Fix the processing of multiple patch files with --check in git-apply.
* New option --ignore-whitespace for git-apply.
* New option --ignore-applied for git-apply.

*** t4104-apply-complex.sh ***
* FAIL 5: S = Nx Px1
	cat Nx Px1 | git-apply -
* FAIL 6: S = Nx Px1 Px2
	cat Nx Px1 Px2 | git-apply -
* FAIL 7: S = Nx Px1 Px2 Px3
	cat Nx Px1 Px2 Px3 | git-apply -
* FAIL 8: S = Nx Px1 Px2 Px3 Dx
	cat Nx Px1 Px2 Px3 Dx | git-apply -
* FAIL 13: S = Ny Ryx Px1 Px2 Cxy Px3 Dx
	cat Ny Ryx Px1 Px2 Cxy Px3 Dx | git-apply -
* FAIL 14: S = Ny Ryx Px1 Px2 Cxy Px3 Dx Cyx
	cat Ny Ryx Px1 Px2 Cxy Px3 Dx Cyx | git-apply -
* FAIL 15: S = Ny Cyx Px1 Px2 Px3 Dy Cxy Dx Cyx Dy Rxy Dy
	cat Ny Cyx Px1 Px2 Px3 Dy Cxy Dx Cyx Dy Rxy Dy| git-apply -

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Robert Fitzsimons]

I should have mentioned before, these changes are being used in a
SourcePuller dump file to git import script I've been working on.

> I further wanted to apply the following to the proposed updates
> branch, but even with only the first one applied, it fails its
> own test, t4104-apply-complex.sh:

The test was the problem it tried to work with empty files.

> * Fix processing of a patch file which modifies the same file in git-apply.
> * Fix the processing of multiple patch files with --check in git-apply.
> * New option --ignore-applied for git-apply.

I've fixed up the problems with these patches and rebased them.

> * New option --ignore-whitespace for git-apply.

This change was just wrong and could cause file corruption, I've got
another version in the works which fixes the problem and adds some of
the suggested features.

Robert Fitzsimons
robfitz@273k.net

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Linus Torvalds]

On Mon, 29 Aug 2005, Robert Fitzsimons wrote:
>
> I should have mentioned before, these changes are being used in a
> SourcePuller dump file to git import script I've been working on.

Hmm. Anything that depends on "--ignore-applied" is fundamentally broken
as an import tool. There's no way something like that can be valid, since
it inhently means that somebody is trying to apply a patch that simple
isn't applicable.

So it seems like you're trying to work around some other serious problems 
in the import, and as a result the import is clearly not trustworthy. 

Don't do this.

			Linus

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Junio C Hamano]

Linus Torvalds <torvalds@osdl.org> writes:

> Hmm. Anything that depends on "--ignore-applied" is fundamentally broken
> as an import tool. There's no way something like that can be valid, since
> it inhently means that somebody is trying to apply a patch that simple
> isn't applicable.
>
> Don't do this.

I suspect that it is exported data that is broken, if
this --ignore-applied flag is needed for importing something
somebody exported.

I, however, am not 100% convinced --ignore-applied is too
dangerous to be useful in any conceivable use cases, at least
not yet.  For example, you might be cherry-picking a change from
a foreign branch with 'git-diff-tree -p other~45 | git apply',
where the current branch may have already aquired part of the
changes that foreign branch contains since 45 generations ago.

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Linus Torvalds]

On Mon, 29 Aug 2005, Junio C Hamano wrote:
> 
> I, however, am not 100% convinced --ignore-applied is too
> dangerous to be useful in any conceivable use cases, at least
> not yet.  For example, you might be cherry-picking a change from
> a foreign branch with 'git-diff-tree -p other~45 | git apply',
> where the current branch may have already aquired part of the
> changes that foreign branch contains since 45 generations ago.

.. and that's why we use a three-way merge, and not diffs, to merge two 
branches. 

--ignore-applied really is a pretty dangerous thing. I can see that it 
might do the right thing in many cases, but definitely not in a scripted 
environment, much less in an "import". 

By definition, importing stuff must apply, since it clearly applied in
whatever original source control tool you are importing from. So if an 
importer needs --ignore-applied, it is fundamentally doing something 
wrong.

And I just realized what "SourcePuller" is. Gaah. Trust me, that export is 
bad, and the original source control tool did everything very well indeed.

			Linus

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Junio C Hamano]

Linus Torvalds <torvalds@osdl.org> writes:

> On Mon, 29 Aug 2005, Junio C Hamano wrote:
>> 
>> I, however, am not 100% convinced --ignore-applied is too
>> dangerous to be useful in any conceivable use cases, at least
>> not yet.  For example, you might be cherry-picking a change from
>> a foreign branch with 'git-diff-tree -p other~45 | git apply',
>> where the current branch may have already aquired part of the
>> changes that foreign branch contains since 45 generations ago.
>
> .. and that's why we use a three-way merge, and not diffs, to merge two 
> branches. 

.. and that's why I recently rewrote revert, cherry-pick and
rebase to use three-way merge as well ;-).

The code is simple enough and I see some beauty in it, but I
honor your veto, at least for now.

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Linus Torvalds]

On Mon, 29 Aug 2005, Junio C Hamano wrote:
> 
> The code is simple enough and I see some beauty in it, but I
> honor your veto, at least for now.

Well, I didn't actually veto it when I saw the feature the first time, 
because I think it's a valid thing to do when applying patches by hand.

It was only when I realized that Robert was trying to use it to import 
from somewhere else that it became broken. An import should use the most 
anal patches possible.

Actually, an import should preferably never use patches at all, since that
never really works for binary data. This is why the CVS importer actually
checks out full files and imports them that way. The patch-based ones will 
fundamentally always have problems.

		Linus

Re: [PATCH 1/9] Fix git patch header processing in git-apply.

[Martin Langhoff]

On 8/30/05, Linus Torvalds <torvalds@osdl.org> wrote:
> Actually, an import should preferably never use patches at all, since that
> never really works for binary data. This is why the CVS importer actually
> checks out full files and imports them that way. The patch-based ones will
> fundamentally always have problems.

<AOL>. Patches can be useful during the process, but you should (a)
prefer more solid manifestations of the file/tree if possible, and (b)
be extremely strict with them. Any hint that they don't match means
that something is borked.

However, if you're importing from patch-oriented SCMs that tend to
'replay' patch sequences from one branch to the other, asking git to
skip applied patches *could* be a shortcut. Not 100% correctness
guarantee, but if the resulting history makes sense, it can be useful.

The other alternative is to do what I'll start to do soon on the
archimport script: keep a tally of what was merged where according to
the records that the source SCM has.

cheers,


martin