Add support for GIT_CEILING_DIRS

Make git recognize a new environment variable that prevents it from chdir'ing up into specified directories when looking for a GIT_DIR. Useful for avoiding slow network directories.

Signed-off-by David Reiss <[email protected]>

---
Just a bit of context about the motivation for this. I use git in an environment where homedirs are automounted and "ls /home/nonexistent" takes about 9 seconds.

setup.c +0 -0

index c54f2b6..d7d986c 100644

setup.c +13 -10

@@ -443,17 +476,29 @@ const char *setup_git_directory_gently(int *nongit_ok)
 			check_repository_format_gently(nongit_ok);
 			return NULL;
 		}
-		do {
-			if (!offset) {
-				if (nongit_ok) {
-					if (chdir(cwd))
-						die("Cannot come back to cwd");
-					*nongit_ok = 1;
-					return NULL;
-				}
-				die("Not a git repository");
+
+		// Did we just check the root dir?
+		if (!offset) {
+		not_a_repo:
+			if (nongit_ok) {
+				if (chdir(cwd))
+					die("Cannot come back to cwd");
+				*nongit_ok = 1;
+				return NULL;
 			}
-		} while (cwd[--offset] != '/');
+			die("Not a git repository");
+		}
+
+		while (cwd[--offset] != '/') {

t/t1504-ceiling-dirs.sh new file +8 -0

new file mode 100755
index 0000000..d4eaa13
@@ -0,0 +1,104 @@
+#!/bin/sh
+
+test_description='test GIT_CEILING_DIRS'
+. ./test-lib.sh
+
+test_prefix() {
+	test_expect_success "$1" \
+	"test '$2' = \"\$(git rev-parse --show-prefix)\""

Quoted 9 lines · David Reiss

setup.c +1 -0

index c54f2b6..d7d986c 100644
@@ -359,10 +359,11 @@ const char *read_gitfile_gently(const char *path)
 const char *setup_git_directory_gently(int *nongit_ok)
 {
 	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
+	const char *env_ceiling_dirs = getenv(CEILING_DIRS_ENVIRONMENT);

setup.c const char *read_gitfile_gently(const char *path) · line 366

Quoted 5 lines

setup.c +1 -1

 	static char cwd[PATH_MAX+1];
 	const char *gitdirenv;
 	const char *gitfile_dir;
-	int len, offset;
+	int len, offset, min_offset = -1;

AFAIR we have min_offset in the mingw branch, too, but I think it is initialized to 0.

setup.c const char *setup_git_directory_gently(int · line 419

Quoted 6 lines

setup.c +1 -0

@@ -414,6 +415,37 @@ const char *setup_git_directory_gently(int  
 *nongit_ok)
 	if (!getcwd(cwd, sizeof(cwd)-1))
 		die("Unable to read current working directory");
 
+	// Compute min_offset based on GIT_CEILING_DIRS.

We do not like C99 style comments. Remember, there are people who compile Git on something else than the super-latest Linux with cutting-edge GCC.

Quoted 4 lines · Johannes Schindelin

Quoted 4 lines

setup.c +0 -0

@@ -414,6 +415,37 @@ const char *setup_git_directory_gently(int *nongit_ok)
 if (!getcwd(cwd, sizeof(cwd)-1))
 die("Unable to read current working directory");
 

Quoted 4 lines

setup.c const char *setup_git_directory_gently(int *nongit_ok) · line 418

Quoted 1 line

setup.c +1 -0

+	// Compute min_offset based on GIT_CEILING_DIRS.

We do not like C99 style comments. Remember, there are people who compile Git on something else than the super-latest Linux with cutting-edge GCC.

Out of curiosity, what environment these days doesn't allow C99 comments?

Quoted 7 lines · Kevin Ballard

Quoted 5 lines · Johannes Schindelin

Quoted 5 lines

setup.c +0 -0

@@ -414,6 +415,37 @@ const char *setup_git_directory_gently(int  
 *nongit_ok)
 if (!getcwd(cwd, sizeof(cwd)-1))
 die("Unable to read current working directory");
 

Quoted 6 lines

Quoted 4 lines

setup.c const char *setup_git_directory_gently(int *nongit_ok) · line 418

Quoted 1 line

setup.c +1 -0

+	// Compute min_offset based on GIT_CEILING_DIRS.

We do not like C99 style comments. Remember, there are people who compile Git on something else than the super-latest Linux with cutting-edge GCC.

Out of curiosity, what environment these days doesn't allow C99 comments?

On an SGI/IRIX machine I was working some time ago, GCC was too big for my quota. And the admin was not willing to install it.

But I have to wonder: why argue something as C99 comments, when it is _no problem_ whatsoever to replace them with C89-style comments, especially given the fact that this makes our source code more consistent and thus easier on the eye?