[PATCH 0/3] Rename make_*_path with clearer names

[PATCH 0/3] Rename make_*_path with clearer names

[Carlos Martín Nieto]

The first patch in this series is in fact a memory-access, but they
together logically as enhancements to make_*_path. Just say so if
it'd be better to split them up.

The calls have been converted 1-to-1 to use the new names, as the real
resolved path is what is needed most of the time.

Carlos Martín Nieto (3):
  make_absolute_path: return the input path if it points to our buffer
  Name make_*_path functions more accurately
  Use the new {real,absolute}_path function names

 abspath.c              |   26 +++++++++++++++++++++++---
 builtin/clone.c        |   12 ++++++------
 builtin/init-db.c      |    8 ++++----
 builtin/receive-pack.c |    2 +-
 cache.h                |    6 +++---
 dir.c                  |    4 ++--
 environment.c          |    4 ++--
 exec_cmd.c             |    2 +-
 lockfile.c             |    4 ++--
 path.c                 |    2 +-
 setup.c                |   14 ++++++--------
 t/t0000-basic.sh       |   10 +++++-----
 test-path-utils.c      |    4 ++--
 13 files changed, 58 insertions(+), 40 deletions(-)

-- 
1.7.4.1

[PATCH 1/3] make_absolute_path: return the input path if it points to our buffer

[Carlos Martín Nieto]

Some codepaths call make_absolute_path with its own return value as
input. In such a cases, return the path immediately.

This fixes a valgrind-discovered error, whereby we tried to copy a
string onto itself.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
---
 abspath.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/abspath.c b/abspath.c
index 91ca00f..ff14068 100644
--- a/abspath.c
+++ b/abspath.c
@@ -24,6 +24,10 @@ const char *make_absolute_path(const char *path)
 	char *last_elem = NULL;
 	struct stat st;
 
+	/* We've already done it */
+	if (path == buf || path == next_buf)
+		return path;
+
 	if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 		die ("Too long path: %.*s", 60, path);
 
-- 
1.7.4.1

[PATCH 2/3] Name make_*_path functions more accurately

[Carlos Martín Nieto]

Rename the make_*_path functions so it's clearer what they do, in
particlar make clear what the differnce between make_absolute_path and
make_nonrelative_path is by renaming them real_path and absolute_path
respectively. make_relative_path has an understandable name and is
renamed to relative_path to maintain the name convention.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
---
 abspath.c         |   22 +++++++++++++++++++---
 cache.h           |    6 +++---
 path.c            |    2 +-
 t/t0000-basic.sh  |   10 +++++-----
 test-path-utils.c |    4 ++--
 5 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/abspath.c b/abspath.c
index ff14068..47bc73e 100644
--- a/abspath.c
+++ b/abspath.c
@@ -14,7 +14,14 @@ int is_directory(const char *path)
 /* We allow "recursive" symbolic links. Only within reason, though. */
 #define MAXDEPTH 5
 
-const char *make_absolute_path(const char *path)
+/*
+ * Use this to get the real path, i.e. resolve links. If you want an
+ * absolute path but don't mind links, use absolute_path.
+ *
+ * If path is our buffer, then return path, as it's already what the
+ * user wants.
+ */
+const char *real_path(const char *path)
 {
 	static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
 	char cwd[1024] = "";
@@ -104,13 +111,22 @@ static const char *get_pwd_cwd(void)
 	return cwd;
 }
 
-const char *make_nonrelative_path(const char *path)
+/*
+ * Use this to get an absolute path from a relative one. If you want
+ * to resolve links, you should use real_path.
+ *
+ * If the path is already absolute, then return path. As the user is
+ * never meant to free the return value, we're safe.
+ */
+const char *absolute_path(const char *path)
 {
 	static char buf[PATH_MAX + 1];
 
 	if (is_absolute_path(path)) {
-		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
+		if (strlen(path) >= PATH_MAX)
 			die("Too long path: %.*s", 60, path);
+		else
+			return path;
 	} else {
 		size_t len;
 		const char *fmt;
diff --git a/cache.h b/cache.h
index c7b0a28..dbc87be 100644
--- a/cache.h
+++ b/cache.h
@@ -716,9 +716,9 @@ static inline int is_absolute_path(const char *path)
 	return path[0] == '/' || has_dos_drive_prefix(path);
 }
 int is_directory(const char *);
-const char *make_absolute_path(const char *path);
-const char *make_nonrelative_path(const char *path);
-const char *make_relative_path(const char *abs, const char *base);
+const char *real_path(const char *path);
+const char *absolute_path(const char *path);
+const char *relative_path(const char *abs, const char *base);
 int normalize_path_copy(char *dst, const char *src);
 int longest_ancestor_length(const char *path, const char *prefix_list);
 char *strip_path_suffix(const char *path, const char *suffix);
diff --git a/path.c b/path.c
index 8951333..4d73cc9 100644
--- a/path.c
+++ b/path.c
@@ -397,7 +397,7 @@ int set_shared_perm(const char *path, int mode)
 	return 0;
 }
 
-const char *make_relative_path(const char *abs, const char *base)
+const char *relative_path(const char *abs, const char *base)
 {
 	static char buf[PATH_MAX + 1];
 	int i = 0, j = 0;
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 8deec75..f4e8f43 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -435,7 +435,7 @@ test_expect_success 'update-index D/F conflict' '
 	test $numpath0 = 1
 '
 
-test_expect_success SYMLINKS 'absolute path works as expected' '
+test_expect_success SYMLINKS 'real path works as expected' '
 	mkdir first &&
 	ln -s ../.git first/.git &&
 	mkdir second &&
@@ -443,14 +443,14 @@ test_expect_success SYMLINKS 'absolute path works as expected' '
 	mkdir third &&
 	dir="$(cd .git; pwd -P)" &&
 	dir2=third/../second/other/.git &&
-	test "$dir" = "$(test-path-utils make_absolute_path $dir2)" &&
+	test "$dir" = "$(test-path-utils real_path $dir2)" &&
 	file="$dir"/index &&
-	test "$file" = "$(test-path-utils make_absolute_path $dir2/index)" &&
+	test "$file" = "$(test-path-utils real_path $dir2/index)" &&
 	basename=blub &&
-	test "$dir/$basename" = "$(cd .git && test-path-utils make_absolute_path "$basename")" &&
+	test "$dir/$basename" = "$(cd .git && test-path-utils real_path "$basename")" &&
 	ln -s ../first/file .git/syml &&
 	sym="$(cd first; pwd -P)"/file &&
-	test "$sym" = "$(test-path-utils make_absolute_path "$dir2/syml")"
+	test "$sym" = "$(test-path-utils real_path "$dir2/syml")"
 '
 
 test_expect_success 'very long name in the index handled sanely' '
diff --git a/test-path-utils.c b/test-path-utils.c
index d261398..e767159 100644
--- a/test-path-utils.c
+++ b/test-path-utils.c
@@ -11,9 +11,9 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
-	if (argc >= 2 && !strcmp(argv[1], "make_absolute_path")) {
+	if (argc >= 2 && !strcmp(argv[1], "real_path")) {
 		while (argc > 2) {
-			puts(make_absolute_path(argv[2]));
+			puts(real_path(argv[2]));
 			argc--;
 			argv++;
 		}
-- 
1.7.4.1

[PATCH 3/3] Use the new {real,absolute}_path function names

[Carlos Martín Nieto]

Use the new names for path functions in the code. Replace uses of
make_absolute_path with real_path, make_nonrelative_path with
absolute_path and make_relative_path with relative_path.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
---
 builtin/clone.c        |   12 ++++++------
 builtin/init-db.c      |    8 ++++----
 builtin/receive-pack.c |    2 +-
 dir.c                  |    4 ++--
 environment.c          |    4 ++--
 exec_cmd.c             |    2 +-
 lockfile.c             |    4 ++--
 setup.c                |   14 ++++++--------
 8 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/builtin/clone.c b/builtin/clone.c
index 60d9a64..780809d 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -100,7 +100,7 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 		path = mkpath("%s%s", repo, suffix[i]);
 		if (is_directory(path)) {
 			*is_bundle = 0;
-			return xstrdup(make_nonrelative_path(path));
+			return xstrdup(absolute_path(path));
 		}
 	}
 
@@ -109,7 +109,7 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 		path = mkpath("%s%s", repo, bundle_suffix[i]);
 		if (!stat(path, &st) && S_ISREG(st.st_mode)) {
 			*is_bundle = 1;
-			return xstrdup(make_nonrelative_path(path));
+			return xstrdup(absolute_path(path));
 		}
 	}
 
@@ -203,7 +203,7 @@ static void setup_reference(const char *repo)
 	struct transport *transport;
 	const struct ref *extra;
 
-	ref_git = make_absolute_path(option_reference);
+	ref_git = real_path(option_reference);
 
 	if (is_directory(mkpath("%s/.git/objects", ref_git)))
 		ref_git = mkpath("%s/.git", ref_git);
@@ -411,9 +411,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	path = get_repo_path(repo_name, &is_bundle);
 	if (path)
-		repo = xstrdup(make_nonrelative_path(repo_name));
+		repo = xstrdup(absolute_path(repo_name));
 	else if (!strchr(repo_name, ':'))
-		repo = xstrdup(make_absolute_path(repo_name));
+		repo = xstrdup(real_path(repo_name));
 	else
 		repo = repo_name;
 	is_local = path && !is_bundle;
@@ -466,7 +466,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	if (safe_create_leading_directories_const(git_dir) < 0)
 		die("could not create leading directories of '%s'", git_dir);
-	set_git_dir(make_absolute_path(git_dir));
+	set_git_dir(real_path(git_dir));
 
 	if (0 <= option_verbosity)
 		printf("Cloning into %s%s...\n",
diff --git a/builtin/init-db.c b/builtin/init-db.c
index fbeb380..63cf259 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -501,7 +501,7 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 		const char *git_dir_parent = strrchr(git_dir, '/');
 		if (git_dir_parent) {
 			char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
-			git_work_tree_cfg = xstrdup(make_absolute_path(rel));
+			git_work_tree_cfg = xstrdup(real_path(rel));
 			free(rel);
 		}
 		if (!git_work_tree_cfg) {
@@ -510,7 +510,7 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 				die_errno ("Cannot access current working directory");
 		}
 		if (work_tree)
-			set_git_work_tree(make_absolute_path(work_tree));
+		  set_git_work_tree(real_path(work_tree));
 		else
 			set_git_work_tree(git_work_tree_cfg);
 		if (access(get_git_work_tree(), X_OK))
@@ -519,10 +519,10 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	}
 	else {
 		if (work_tree)
-			set_git_work_tree(make_absolute_path(work_tree));
+			set_git_work_tree(real_path(work_tree));
 	}
 
-	set_git_dir(make_absolute_path(git_dir));
+	set_git_dir(real_path(git_dir));
 
 	return init_db(template_dir, flags);
 }
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 760817d..d883585 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -740,7 +740,7 @@ static int add_refs_from_alternate(struct alternate_object_database *e, void *un
 	const struct ref *extra;
 
 	e->name[-1] = '\0';
-	other = xstrdup(make_absolute_path(e->base));
+	other = xstrdup(real_path(e->base));
 	e->name[-1] = '/';
 	len = strlen(other);
 
diff --git a/dir.c b/dir.c
index 570b651..5a9372a 100644
--- a/dir.c
+++ b/dir.c
@@ -1023,8 +1023,8 @@ char *get_relative_cwd(char *buffer, int size, const char *dir)
 	if (!getcwd(buffer, size))
 		die_errno("can't find the current directory");
 
-	if (!is_absolute_path(dir))
-		dir = make_absolute_path(dir);
+	/* getcwd resolves links and gives us the real path */
+	dir = real_path(dir);
 
 	while (*dir && *dir == *cwd) {
 		dir++;
diff --git a/environment.c b/environment.c
index c3efbb9..cc670b1 100644
--- a/environment.c
+++ b/environment.c
@@ -139,7 +139,7 @@ static int git_work_tree_initialized;
 void set_git_work_tree(const char *new_work_tree)
 {
 	if (git_work_tree_initialized) {
-		new_work_tree = make_absolute_path(new_work_tree);
+		new_work_tree = real_path(new_work_tree);
 		if (strcmp(new_work_tree, work_tree))
 			die("internal error: work tree has already been set\n"
 			    "Current worktree: %s\nNew worktree: %s",
@@ -147,7 +147,7 @@ void set_git_work_tree(const char *new_work_tree)
 		return;
 	}
 	git_work_tree_initialized = 1;
-	work_tree = xstrdup(make_absolute_path(new_work_tree));
+	work_tree = xstrdup(real_path(new_work_tree));
 }
 
 const char *get_git_work_tree(void)
diff --git a/exec_cmd.c b/exec_cmd.c
index 38545e8..171e841 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -89,7 +89,7 @@ static void add_path(struct strbuf *out, const char *path)
 		if (is_absolute_path(path))
 			strbuf_addstr(out, path);
 		else
-			strbuf_addstr(out, make_nonrelative_path(path));
+			strbuf_addstr(out, absolute_path(path));
 
 		strbuf_addch(out, PATH_SEP);
 	}
diff --git a/lockfile.c b/lockfile.c
index b0d74cd..c6fb77b 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -164,10 +164,10 @@ static char *unable_to_lock_message(const char *path, int err)
 		    "If no other git process is currently running, this probably means a\n"
 		    "git process crashed in this repository earlier. Make sure no other git\n"
 		    "process is running and remove the file manually to continue.",
-			    make_nonrelative_path(path), strerror(err));
+			    absolute_path(path), strerror(err));
 	} else
 		strbuf_addf(&buf, "Unable to create '%s.lock': %s",
-			    make_nonrelative_path(path), strerror(err));
+			    absolute_path(path), strerror(err));
 	return strbuf_detach(&buf, NULL);
 }
 
diff --git a/setup.c b/setup.c
index dadc666..8cb1ad3 100644
--- a/setup.c
+++ b/setup.c
@@ -216,9 +216,7 @@ void setup_work_tree(void)
 	if (initialized)
 		return;
 	work_tree = get_git_work_tree();
-	git_dir = get_git_dir();
-	if (!is_absolute_path(git_dir))
-		git_dir = make_absolute_path(git_dir);
+	git_dir = real_path(get_git_dir());
 	if (!work_tree || chdir(work_tree))
 		die("This operation must be run in a work tree");
 
@@ -229,7 +227,7 @@ void setup_work_tree(void)
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 		setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 
-	set_git_dir(make_relative_path(git_dir, work_tree));
+	set_git_dir(relative_path(git_dir, work_tree));
 	initialized = 1;
 }
 
@@ -309,7 +307,7 @@ const char *read_gitfile_gently(const char *path)
 
 	if (!is_git_directory(dir))
 		die("Not a git repository: %s", dir);
-	path = make_absolute_path(dir);
+	path = real_path(dir);
 
 	free(buf);
 	return path;
@@ -389,7 +387,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 
 	if (!prefixcmp(cwd, worktree) &&
 	    cwd[strlen(worktree)] == '/') { /* cwd inside worktree */
-		set_git_dir(make_absolute_path(gitdirenv));
+		set_git_dir(real_path(gitdirenv));
 		if (chdir(worktree))
 			die_errno("Could not chdir to '%s'", worktree);
 		cwd[len++] = '/';
@@ -414,7 +412,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 	/* --work-tree is set without --git-dir; use discovered one */
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 		if (offset != len && !is_absolute_path(gitdir))
-			gitdir = xstrdup(make_absolute_path(gitdir));
+			gitdir = xstrdup(real_path(gitdir));
 		if (chdir(cwd))
 			die_errno("Could not come back to cwd");
 		return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
@@ -422,7 +420,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 
 	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 	if (is_bare_repository_cfg > 0) {
-		set_git_dir(offset == len ? gitdir : make_absolute_path(gitdir));
+		set_git_dir(offset == len ? gitdir : real_path(gitdir));
 		if (chdir(cwd))
 			die_errno("Could not come back to cwd");
 		return NULL;
-- 
1.7.4.1

Re: [PATCH 3/3] Use the new {real,absolute}_path function names

[Erik Faye-Lund]

On Wed, Mar 16, 2011 at 5:06 PM, Carlos Martín Nieto <cmn@elego.de> wrote:
> Use the new names for path functions in the code. Replace uses of
> make_absolute_path with real_path, make_nonrelative_path with
> absolute_path and make_relative_path with relative_path.

Shouldn't these changes be squashed into the previous two commits so
it'll be possible to bisect across it without getting a broken build?

Re: [PATCH 2/3] Name make_*_path functions more accurately

[Brian Gernhardt]

On Mar 16, 2011, at 12:06 PM, Carlos Martín Nieto wrote:

> Rename the make_*_path functions so it's clearer what they do, in
> particlar make clear what the differnce between make_absolute_path and
> make_nonrelative_path is by renaming them real_path and absolute_path
> respectively. make_relative_path has an understandable name and is
> renamed to relative_path to maintain the name convention.
> 
> Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

I didn't try it, but it looks like 2/3 horribly breaks the code and 3/3 fixes it.  I personally (and I think others) prefer patches that are each useful on their own.  Especially since a code-breaking patch like this makes bisecting harder.

I would suggest doing one of the following:

1) Squashing 2/3 and 3/3 so all the renaming occurs at once.
2) Adding wrappers from the old name to the new in 2/3 and removing them in 3/3.

That said, I'm not sure the renaming is useful although the documentation comments definitely are.

~~ Brian

Re: [PATCH 3/3] Use the new {real,absolute}_path function names

[Carlos Martín Nieto]

On mié, 2011-03-16 at 17:24 +0100, Erik Faye-Lund wrote:
> On Wed, Mar 16, 2011 at 5:06 PM, Carlos Martín Nieto <cmn@elego.de> wrote:
> > Use the new names for path functions in the code. Replace uses of
> > make_absolute_path with real_path, make_nonrelative_path with
> > absolute_path and make_relative_path with relative_path.
> 
> Shouldn't these changes be squashed into the previous two commits so
> it'll be possible to bisect across it without getting a broken build?

 Brian pointed this out in the other subthread. I'll resend.

Re: [PATCH 2/3] Name make_*_path functions more accurately

[Carlos Martín Nieto]

On mié, 2011-03-16 at 12:29 -0400, Brian Gernhardt wrote:
> On Mar 16, 2011, at 12:06 PM, Carlos Martín Nieto wrote:
> 
> > Rename the make_*_path functions so it's clearer what they do, in
> > particlar make clear what the differnce between make_absolute_path and
> > make_nonrelative_path is by renaming them real_path and absolute_path
> > respectively. make_relative_path has an understandable name and is
> > renamed to relative_path to maintain the name convention.
> > 
> > Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
> 
> I didn't try it, but it looks like 2/3 horribly breaks the code and
> 3/3 fixes it.  I personally (and I think others) prefer patches that
> are each useful on their own.  Especially since a code-breaking patch
> like this makes bisecting harder.

 True enough.

> 
> I would suggest doing one of the following:
> 
> 1) Squashing 2/3 and 3/3 so all the renaming occurs at once.
> 2) Adding wrappers from the old name to the new in 2/3 and removing
> them in 3/3.

 I'll squash.

> 
> That said, I'm not sure the renaming is useful although the
> documentation comments definitely are.

 Do you think the difference between make_nonrelative_path and
make_absolute_path is clear without looking at the code? For me at
least, a relative path is the opposite of an absolute one, and a
non-relative path is the opposite of a relative one. To make a
difference between absolute and non-relative is then bound to lead to
errors.

   cmn

[PATCH 2-3/3] Name make_*_path functions more accurately

[Carlos Martín Nieto]

Rename the make_*_path functions so it's clearer what they do, in
particlar make clear what the differnce between make_absolute_path and
make_nonrelative_path is by renaming them real_path and absolute_path
respectively. make_relative_path has an understandable name and is
renamed to relative_path to maintain the name convention.

The function calls have been replaced 1-to-1 in their usage.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
---

Sorry, I sent the other one without in-reply-to information

This supercedes the 2/3 and 3/3 patches.

 abspath.c              |   22 +++++++++++++++++++---
 builtin/clone.c        |   12 ++++++------
 builtin/init-db.c      |    8 ++++----
 builtin/receive-pack.c |    2 +-
 cache.h                |    6 +++---
 dir.c                  |    4 ++--
 environment.c          |    4 ++--
 exec_cmd.c             |    2 +-
 lockfile.c             |    4 ++--
 path.c                 |    2 +-
 setup.c                |   14 ++++++--------
 t/t0000-basic.sh       |   10 +++++-----
 test-path-utils.c      |    4 ++--
 13 files changed, 54 insertions(+), 40 deletions(-)

diff --git a/abspath.c b/abspath.c
index ff14068..47bc73e 100644
--- a/abspath.c
+++ b/abspath.c
@@ -14,7 +14,14 @@ int is_directory(const char *path)
 /* We allow "recursive" symbolic links. Only within reason, though. */
 #define MAXDEPTH 5
 
-const char *make_absolute_path(const char *path)
+/*
+ * Use this to get the real path, i.e. resolve links. If you want an
+ * absolute path but don't mind links, use absolute_path.
+ *
+ * If path is our buffer, then return path, as it's already what the
+ * user wants.
+ */
+const char *real_path(const char *path)
 {
 	static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
 	char cwd[1024] = "";
@@ -104,13 +111,22 @@ static const char *get_pwd_cwd(void)
 	return cwd;
 }
 
-const char *make_nonrelative_path(const char *path)
+/*
+ * Use this to get an absolute path from a relative one. If you want
+ * to resolve links, you should use real_path.
+ *
+ * If the path is already absolute, then return path. As the user is
+ * never meant to free the return value, we're safe.
+ */
+const char *absolute_path(const char *path)
 {
 	static char buf[PATH_MAX + 1];
 
 	if (is_absolute_path(path)) {
-		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
+		if (strlen(path) >= PATH_MAX)
 			die("Too long path: %.*s", 60, path);
+		else
+			return path;
 	} else {
 		size_t len;
 		const char *fmt;
diff --git a/builtin/clone.c b/builtin/clone.c
index 60d9a64..780809d 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -100,7 +100,7 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 		path = mkpath("%s%s", repo, suffix[i]);
 		if (is_directory(path)) {
 			*is_bundle = 0;
-			return xstrdup(make_nonrelative_path(path));
+			return xstrdup(absolute_path(path));
 		}
 	}
 
@@ -109,7 +109,7 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 		path = mkpath("%s%s", repo, bundle_suffix[i]);
 		if (!stat(path, &st) && S_ISREG(st.st_mode)) {
 			*is_bundle = 1;
-			return xstrdup(make_nonrelative_path(path));
+			return xstrdup(absolute_path(path));
 		}
 	}
 
@@ -203,7 +203,7 @@ static void setup_reference(const char *repo)
 	struct transport *transport;
 	const struct ref *extra;
 
-	ref_git = make_absolute_path(option_reference);
+	ref_git = real_path(option_reference);
 
 	if (is_directory(mkpath("%s/.git/objects", ref_git)))
 		ref_git = mkpath("%s/.git", ref_git);
@@ -411,9 +411,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	path = get_repo_path(repo_name, &is_bundle);
 	if (path)
-		repo = xstrdup(make_nonrelative_path(repo_name));
+		repo = xstrdup(absolute_path(repo_name));
 	else if (!strchr(repo_name, ':'))
-		repo = xstrdup(make_absolute_path(repo_name));
+		repo = xstrdup(real_path(repo_name));
 	else
 		repo = repo_name;
 	is_local = path && !is_bundle;
@@ -466,7 +466,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	if (safe_create_leading_directories_const(git_dir) < 0)
 		die("could not create leading directories of '%s'", git_dir);
-	set_git_dir(make_absolute_path(git_dir));
+	set_git_dir(real_path(git_dir));
 
 	if (0 <= option_verbosity)
 		printf("Cloning into %s%s...\n",
diff --git a/builtin/init-db.c b/builtin/init-db.c
index fbeb380..63cf259 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -501,7 +501,7 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 		const char *git_dir_parent = strrchr(git_dir, '/');
 		if (git_dir_parent) {
 			char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
-			git_work_tree_cfg = xstrdup(make_absolute_path(rel));
+			git_work_tree_cfg = xstrdup(real_path(rel));
 			free(rel);
 		}
 		if (!git_work_tree_cfg) {
@@ -510,7 +510,7 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 				die_errno ("Cannot access current working directory");
 		}
 		if (work_tree)
-			set_git_work_tree(make_absolute_path(work_tree));
+		  set_git_work_tree(real_path(work_tree));
 		else
 			set_git_work_tree(git_work_tree_cfg);
 		if (access(get_git_work_tree(), X_OK))
@@ -519,10 +519,10 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	}
 	else {
 		if (work_tree)
-			set_git_work_tree(make_absolute_path(work_tree));
+			set_git_work_tree(real_path(work_tree));
 	}
 
-	set_git_dir(make_absolute_path(git_dir));
+	set_git_dir(real_path(git_dir));
 
 	return init_db(template_dir, flags);
 }
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 760817d..d883585 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -740,7 +740,7 @@ static int add_refs_from_alternate(struct alternate_object_database *e, void *un
 	const struct ref *extra;
 
 	e->name[-1] = '\0';
-	other = xstrdup(make_absolute_path(e->base));
+	other = xstrdup(real_path(e->base));
 	e->name[-1] = '/';
 	len = strlen(other);
 
diff --git a/cache.h b/cache.h
index c7b0a28..dbc87be 100644
--- a/cache.h
+++ b/cache.h
@@ -716,9 +716,9 @@ static inline int is_absolute_path(const char *path)
 	return path[0] == '/' || has_dos_drive_prefix(path);
 }
 int is_directory(const char *);
-const char *make_absolute_path(const char *path);
-const char *make_nonrelative_path(const char *path);
-const char *make_relative_path(const char *abs, const char *base);
+const char *real_path(const char *path);
+const char *absolute_path(const char *path);
+const char *relative_path(const char *abs, const char *base);
 int normalize_path_copy(char *dst, const char *src);
 int longest_ancestor_length(const char *path, const char *prefix_list);
 char *strip_path_suffix(const char *path, const char *suffix);
diff --git a/dir.c b/dir.c
index 570b651..5a9372a 100644
--- a/dir.c
+++ b/dir.c
@@ -1023,8 +1023,8 @@ char *get_relative_cwd(char *buffer, int size, const char *dir)
 	if (!getcwd(buffer, size))
 		die_errno("can't find the current directory");
 
-	if (!is_absolute_path(dir))
-		dir = make_absolute_path(dir);
+	/* getcwd resolves links and gives us the real path */
+	dir = real_path(dir);
 
 	while (*dir && *dir == *cwd) {
 		dir++;
diff --git a/environment.c b/environment.c
index c3efbb9..cc670b1 100644
--- a/environment.c
+++ b/environment.c
@@ -139,7 +139,7 @@ static int git_work_tree_initialized;
 void set_git_work_tree(const char *new_work_tree)
 {
 	if (git_work_tree_initialized) {
-		new_work_tree = make_absolute_path(new_work_tree);
+		new_work_tree = real_path(new_work_tree);
 		if (strcmp(new_work_tree, work_tree))
 			die("internal error: work tree has already been set\n"
 			    "Current worktree: %s\nNew worktree: %s",
@@ -147,7 +147,7 @@ void set_git_work_tree(const char *new_work_tree)
 		return;
 	}
 	git_work_tree_initialized = 1;
-	work_tree = xstrdup(make_absolute_path(new_work_tree));
+	work_tree = xstrdup(real_path(new_work_tree));
 }
 
 const char *get_git_work_tree(void)
diff --git a/exec_cmd.c b/exec_cmd.c
index 38545e8..171e841 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -89,7 +89,7 @@ static void add_path(struct strbuf *out, const char *path)
 		if (is_absolute_path(path))
 			strbuf_addstr(out, path);
 		else
-			strbuf_addstr(out, make_nonrelative_path(path));
+			strbuf_addstr(out, absolute_path(path));
 
 		strbuf_addch(out, PATH_SEP);
 	}
diff --git a/lockfile.c b/lockfile.c
index b0d74cd..c6fb77b 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -164,10 +164,10 @@ static char *unable_to_lock_message(const char *path, int err)
 		    "If no other git process is currently running, this probably means a\n"
 		    "git process crashed in this repository earlier. Make sure no other git\n"
 		    "process is running and remove the file manually to continue.",
-			    make_nonrelative_path(path), strerror(err));
+			    absolute_path(path), strerror(err));
 	} else
 		strbuf_addf(&buf, "Unable to create '%s.lock': %s",
-			    make_nonrelative_path(path), strerror(err));
+			    absolute_path(path), strerror(err));
 	return strbuf_detach(&buf, NULL);
 }
 
diff --git a/path.c b/path.c
index 8951333..4d73cc9 100644
--- a/path.c
+++ b/path.c
@@ -397,7 +397,7 @@ int set_shared_perm(const char *path, int mode)
 	return 0;
 }
 
-const char *make_relative_path(const char *abs, const char *base)
+const char *relative_path(const char *abs, const char *base)
 {
 	static char buf[PATH_MAX + 1];
 	int i = 0, j = 0;
diff --git a/setup.c b/setup.c
index dadc666..8cb1ad3 100644
--- a/setup.c
+++ b/setup.c
@@ -216,9 +216,7 @@ void setup_work_tree(void)
 	if (initialized)
 		return;
 	work_tree = get_git_work_tree();
-	git_dir = get_git_dir();
-	if (!is_absolute_path(git_dir))
-		git_dir = make_absolute_path(git_dir);
+	git_dir = real_path(get_git_dir());
 	if (!work_tree || chdir(work_tree))
 		die("This operation must be run in a work tree");
 
@@ -229,7 +227,7 @@ void setup_work_tree(void)
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 		setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 
-	set_git_dir(make_relative_path(git_dir, work_tree));
+	set_git_dir(relative_path(git_dir, work_tree));
 	initialized = 1;
 }
 
@@ -309,7 +307,7 @@ const char *read_gitfile_gently(const char *path)
 
 	if (!is_git_directory(dir))
 		die("Not a git repository: %s", dir);
-	path = make_absolute_path(dir);
+	path = real_path(dir);
 
 	free(buf);
 	return path;
@@ -389,7 +387,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 
 	if (!prefixcmp(cwd, worktree) &&
 	    cwd[strlen(worktree)] == '/') { /* cwd inside worktree */
-		set_git_dir(make_absolute_path(gitdirenv));
+		set_git_dir(real_path(gitdirenv));
 		if (chdir(worktree))
 			die_errno("Could not chdir to '%s'", worktree);
 		cwd[len++] = '/';
@@ -414,7 +412,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 	/* --work-tree is set without --git-dir; use discovered one */
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 		if (offset != len && !is_absolute_path(gitdir))
-			gitdir = xstrdup(make_absolute_path(gitdir));
+			gitdir = xstrdup(real_path(gitdir));
 		if (chdir(cwd))
 			die_errno("Could not come back to cwd");
 		return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
@@ -422,7 +420,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 
 	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 	if (is_bare_repository_cfg > 0) {
-		set_git_dir(offset == len ? gitdir : make_absolute_path(gitdir));
+		set_git_dir(offset == len ? gitdir : real_path(gitdir));
 		if (chdir(cwd))
 			die_errno("Could not come back to cwd");
 		return NULL;
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 8deec75..f4e8f43 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -435,7 +435,7 @@ test_expect_success 'update-index D/F conflict' '
 	test $numpath0 = 1
 '
 
-test_expect_success SYMLINKS 'absolute path works as expected' '
+test_expect_success SYMLINKS 'real path works as expected' '
 	mkdir first &&
 	ln -s ../.git first/.git &&
 	mkdir second &&
@@ -443,14 +443,14 @@ test_expect_success SYMLINKS 'absolute path works as expected' '
 	mkdir third &&
 	dir="$(cd .git; pwd -P)" &&
 	dir2=third/../second/other/.git &&
-	test "$dir" = "$(test-path-utils make_absolute_path $dir2)" &&
+	test "$dir" = "$(test-path-utils real_path $dir2)" &&
 	file="$dir"/index &&
-	test "$file" = "$(test-path-utils make_absolute_path $dir2/index)" &&
+	test "$file" = "$(test-path-utils real_path $dir2/index)" &&
 	basename=blub &&
-	test "$dir/$basename" = "$(cd .git && test-path-utils make_absolute_path "$basename")" &&
+	test "$dir/$basename" = "$(cd .git && test-path-utils real_path "$basename")" &&
 	ln -s ../first/file .git/syml &&
 	sym="$(cd first; pwd -P)"/file &&
-	test "$sym" = "$(test-path-utils make_absolute_path "$dir2/syml")"
+	test "$sym" = "$(test-path-utils real_path "$dir2/syml")"
 '
 
 test_expect_success 'very long name in the index handled sanely' '
diff --git a/test-path-utils.c b/test-path-utils.c
index d261398..e767159 100644
--- a/test-path-utils.c
+++ b/test-path-utils.c
@@ -11,9 +11,9 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
-	if (argc >= 2 && !strcmp(argv[1], "make_absolute_path")) {
+	if (argc >= 2 && !strcmp(argv[1], "real_path")) {
 		while (argc > 2) {
-			puts(make_absolute_path(argv[2]));
+			puts(real_path(argv[2]));
 			argc--;
 			argv++;
 		}
-- 
1.7.4.1

Re: [PATCH 1/3] make_absolute_path: return the input path if it points to our buffer

[Junio C Hamano]

Carlos Martín Nieto <cmn@elego.de> writes:

> Some codepaths call make_absolute_path with its own return value as
> input. In such a cases, return the path immediately.
>
> This fixes a valgrind-discovered error, whereby we tried to copy a
> string onto itself.
>
> Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
> ---
>  abspath.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/abspath.c b/abspath.c
> index 91ca00f..ff14068 100644
> --- a/abspath.c
> +++ b/abspath.c
> @@ -24,6 +24,10 @@ const char *make_absolute_path(const char *path)
>  	char *last_elem = NULL;
>  	struct stat st;
>  
> +	/* We've already done it */
> +	if (path == buf || path == next_buf)
> +		return path;
> +

I like this, as it is very obvious what we are checking here.  Thanks.