[PATCH 08/32] Add $GIT_DIR/narrow check

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This file contains the narrow prefix. With get_narrow_prefix() being
non-empty behavior of git may be totally different.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Makefile      |    2 ++
 cache.h       |    3 +++
 environment.c |    2 ++
 narrow-tree.c |   31 +++++++++++++++++++++++++++++++
 narrow-tree.h |    1 +
 5 files changed, 39 insertions(+), 0 deletions(-)
 create mode 100644 narrow-tree.c
 create mode 100644 narrow-tree.h

diff --git a/Makefile b/Makefile
index 1f11618..54c435e 100644
--- a/Makefile
+++ b/Makefile
@@ -525,6 +525,7 @@ LIB_H += sigchain.h
 LIB_H += strbuf.h
 LIB_H += string-list.h
 LIB_H += submodule.h
+LIB_H += narrow-tree.h
 LIB_H += tag.h
 LIB_H += transport.h
 LIB_H += tree.h
@@ -629,6 +630,7 @@ LIB_OBJS += sigchain.o
 LIB_OBJS += strbuf.o
 LIB_OBJS += string-list.o
 LIB_OBJS += submodule.o
+LIB_OBJS += narrow-tree.o
 LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
 LIB_OBJS += trace.o
diff --git a/cache.h b/cache.h
index 37ef9d8..ff401ec 100644
--- a/cache.h
+++ b/cache.h
@@ -1101,4 +1101,7 @@ int split_cmdline(char *cmdline, const char ***argv);
 /* builtin/merge.c */
 int checkout_fast_forward(const unsigned char *from, const unsigned char *to);
 
+/* narrow-tree.c */
+extern const char *get_narrow_prefix();
+
 #endif /* CACHE_H */
diff --git a/environment.c b/environment.c
index 83d38d3..41fcbd4 100644
--- a/environment.c
+++ b/environment.c
@@ -8,6 +8,7 @@
  * are.
  */
 #include "cache.h"
+#include "narrow-tree.h"
 
 char git_default_email[MAX_GITNAME];
 char git_default_name[MAX_GITNAME];
@@ -105,6 +106,7 @@ static void setup_git_env(void)
 		git_graft_file = git_pathdup("info/grafts");
 	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
 		read_replace_refs = 0;
+	check_narrow_prefix();
 }
 
 int is_bare_repository(void)
diff --git a/narrow-tree.c b/narrow-tree.c
new file mode 100644
index 0000000..46e913d
--- /dev/null
+++ b/narrow-tree.c
@@ -0,0 +1,31 @@
+#include "cache.h"
+#include "narrow-tree.h"
+
+static const char *narrow_prefix;
+
+int check_narrow_prefix()
+{
+	int fd;
+	static char buf[PATH_MAX];
+	int ret;
+
+	fd = open(git_path("narrow"), O_RDONLY);
+	if (fd == -1)
+		return 0;
+
+	ret = read(fd, buf, PATH_MAX);
+	if (ret > 0) {
+		/* $GIT_DIR/narrow is not meant for manual editing, anyway.. */
+		while (ret && buf[ret-1] == '\n')
+			ret--;
+		buf[ret] = '\0';
+		narrow_prefix = buf;
+	}
+	close(fd);
+	return 0;
+}
+
+const char *get_narrow_prefix()
+{
+	return narrow_prefix;
+}
diff --git a/narrow-tree.h b/narrow-tree.h
new file mode 100644
index 0000000..aa8c94f
--- /dev/null
+++ b/narrow-tree.h
@@ -0,0 +1 @@
+extern int check_narrow_prefix();
-- 
1.7.1.rc1.69.g24c2f7