Merge branch 'jk/git-path'

git_path() and mkpath() are handy helper functions but it is easy
to misuse, as the callers need to be careful to keep the number of
active results below 4.  Their uses have been reduced.

* jk/git-path:
  memoize common git-path "constant" files
  get_repo_path: refactor path-allocation
  find_hook: keep our own static buffer
  refs.c: remove_empty_directories can take a strbuf
  refs.c: avoid git_path assignment in lock_ref_sha1_basic
  refs.c: avoid repeated git_path calls in rename_tmp_log
  refs.c: simplify strbufs in reflog setup and writing
  path.c: drop git_path_submodule
  refs.c: remove extra git_path calls from read_loose_refs
  remote.c: drop extraneous local variable from migrate_file
  prefer mkpathdup to mkpath in assignments
  prefer git_pathdup to git_path in some possibly-dangerous cases
  add_to_alternates_file: don't add duplicate entries
  t5700: modernize style
  cache.h: complete set of git_path_submodule helpers
  cache.h: clarify documentation for git_path, et al

1 files changed, 42 insertions, 5 deletions

diff --git a/cache.h b/cache.h
index 14f070ef34..4e25271e59 100644
--- a/cache.h
+++ b/cache.h
@@ -708,23 +708,60 @@ extern int check_repository_format(void);
 #define DATA_CHANGED    0x0020
 #define TYPE_CHANGED    0x0040
 
+/*
+ * Return a statically allocated filename, either generically (mkpath), in
+ * the repository directory (git_path), or in a submodule's repository
+ * directory (git_path_submodule). In all cases, note that the result
+ * may be overwritten by another call to _any_ of the functions. Consider
+ * using the safer "dup" or "strbuf" formats below (in some cases, the
+ * unsafe versions have already been removed).
+ */
+extern const char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+extern const char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+
 extern char *mksnpath(char *buf, size_t n, const char *fmt, ...)
 	__attribute__((format (printf, 3, 4)));
 extern void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
+extern void strbuf_git_path_submodule(struct strbuf *sb, const char *path,
+				      const char *fmt, ...)
+	__attribute__((format (printf, 3, 4)));
 extern char *git_pathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 extern char *mkpathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
-
-/* Return a statically allocated filename matching the sha1 signature */
-extern const char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
-extern const char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
-extern const char *git_path_submodule(const char *path, const char *fmt, ...)
+extern char *git_pathdup_submodule(const char *path, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
+
 extern void report_linked_checkout_garbage(void);
 
 /*
+ * You can define a static memoized git path like:
+ *
+ *    static GIT_PATH_FUNC(git_path_foo, "FOO");
+ *
+ * or use one of the global ones below.
+ */
+#define GIT_PATH_FUNC(func, filename) \
+	const char *func(void) \
+	{ \
+		static char *ret; \
+		if (!ret) \
+			ret = git_pathdup(filename); \
+		return ret; \
+	}
+
+const char *git_path_cherry_pick_head(void);
+const char *git_path_revert_head(void);
+const char *git_path_squash_msg(void);
+const char *git_path_merge_msg(void);
+const char *git_path_merge_rr(void);
+const char *git_path_merge_mode(void);
+const char *git_path_merge_head(void);
+const char *git_path_fetch_head(void);
+const char *git_path_shallow(void);
+
+/*
  * Return the name of the file in the local object database that would
  * be used to store a loose object with the specified sha1.  The
  * return value is a pointer to a statically allocated buffer that is