prune: honor --expire=never

Previously, prune treated an expiration time of 0 to mean that no
expire argument was supplied, and everything should be pruned.  As a
result, "prune --expire=never" would prune all unreachable objects,
regardless of their timestamp.

prune can be called with --expire=never automatically by gc, when the
gc.pruneExpire configuration is set to "never".

Signed-off-by: Adam Simpkins <simpkins@facebook.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-prune.c

@@ -18,13 +18,11 @@ static unsigned long expire;
 static int prune_tmp_object(const char *path, const char *filename)
 {
 	const char *fullpath = mkpath("%s/%s", path, filename);
-	if (expire) {
-		struct stat st;
-		if (lstat(fullpath, &st))
-			return error("Could not stat '%s'", fullpath);
-		if (st.st_mtime > expire)
-			return 0;
-	}
+	struct stat st;
+	if (lstat(fullpath, &st))
+		return error("Could not stat '%s'", fullpath);
+	if (st.st_mtime > expire)
+		return 0;
 	printf("Removing stale temporary file %s\n", fullpath);
 	if (!show_only)
 		unlink_or_warn(fullpath);
@@ -34,13 +32,11 @@ static int prune_tmp_object(const char *path, const char *filename)
 static int prune_object(char *path, const char *filename, const unsigned char *sha1)
 {
 	const char *fullpath = mkpath("%s/%s", path, filename);
-	if (expire) {
-		struct stat st;
-		if (lstat(fullpath, &st))
-			return error("Could not stat '%s'", fullpath);
-		if (st.st_mtime > expire)
-			return 0;
-	}
+	struct stat st;
+	if (lstat(fullpath, &st))
+		return error("Could not stat '%s'", fullpath);
+	if (st.st_mtime > expire)
+		return 0;
 	if (show_only || verbose) {
 		enum object_type type = sha1_object_info(sha1, NULL);
 		printf("%s %s\n", sha1_to_hex(sha1),
@@ -139,6 +135,7 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 	};
 	char *s;
 
+	expire = ULONG_MAX;
 	save_commit_buffer = 0;
 	read_replace_refs = 0;
 	init_revisions(&revs, prefix);

t/t5304-prune.sh

@@ -148,6 +148,38 @@ test_expect_success 'gc --prune=<date>' '
 
 '
 
+test_expect_success 'gc --prune=never' '
+
+	add_blob &&
+	git gc --prune=never &&
+	test -f $BLOB_FILE &&
+	git gc --prune=now &&
+	test ! -f $BLOB_FILE
+
+'
+
+test_expect_success 'gc respects gc.pruneExpire=never' '
+
+	git config gc.pruneExpire never &&
+	add_blob &&
+	git gc &&
+	test -f $BLOB_FILE &&
+	git config gc.pruneExpire now &&
+	git gc &&
+	test ! -f $BLOB_FILE
+
+'
+
+test_expect_success 'prune --expire=never' '
+
+	add_blob &&
+	git prune --expire=never &&
+	test -f $BLOB_FILE &&
+	git prune &&
+	test ! -f $BLOB_FILE
+
+'
+
 test_expect_success 'gc: prune old objects after local clone' '
 	add_blob &&
 	test-chmtime =-$((2*$week+1)) $BLOB_FILE &&