Improved handling of git syntax names with no git repository

This makes "is_git_repository()" return non-NULL for all file names that
match the git name pattern, even if we don't find an actual git
repository there.  That way, we won't fall back to writing out an XML
file with an odd filename.

If there is no actual git repository, we return a special invalid dummy
pointer, and then the git reading and writing routines will catch it and
return the appropriate error.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 24 insertions, 5 deletions

diff --git a/save-git.c b/save-git.c
index 745f26b01..74eab55bb 100644
--- a/save-git.c
+++ b/save-git.c
@@ -924,30 +924,45 @@ struct git_repository *is_git_repository(const char *filename, const char **bran
 	if (!flen)
 		return NULL;
 
+	/*
+	 * This is the "point of no return": the name matches
+	 * the git repository name rules, and we will no longer
+	 * return NULL.
+	 *
+	 * We will either return "dummy_git_repository" and the
+	 * branch pointer will have the _whole_ filename in it,
+	 * or we will return a real git repository with the
+	 * branch pointer being filled in with just the branch
+	 * name.
+	 *
+	 * The actual git reading/writing routines can use this
+	 * to generate proper error messages.
+	 */
+	*branchp = filename;
 	loc = malloc(flen+1);
 	if (!loc)
-		return NULL;
+		return dummy_git_repository;
 	memcpy(loc, filename, flen);
 	loc[flen] = 0;
 
 	branch = malloc(blen+1);
 	if (!branch) {
 		free(loc);
-		return NULL;
+		return dummy_git_repository;
 	}
 	memcpy(branch, filename+flen+1, blen);
 	branch[blen] = 0;
 
 	if (stat(loc, &st) < 0 || !S_ISDIR(st.st_mode)) {
 		free(loc);
-		return NULL;
+		return dummy_git_repository;
 	}
 
 	ret = git_repository_open(&repo, loc);
 	free(loc);
 	if (ret < 0) {
 		free(branch);
-		return NULL;
+		return dummy_git_repository;
 	}
 	*branchp = branch;
 	return repo;
@@ -955,7 +970,11 @@ struct git_repository *is_git_repository(const char *filename, const char **bran
 
 int git_save_dives(struct git_repository *repo, const char *branch, bool select_only)
 {
-	int ret = do_git_save(repo, branch, select_only);
+	int ret;
+
+	if (repo == dummy_git_repository)
+		return report_error("Unable to open git repository '%s'", branch);
+	ret = do_git_save(repo, branch, select_only);
 	git_repository_free(repo);
 	free((void *)branch);
 	return ret;