fsck: allow upgrading fsck warnings to errors

The 'invalid tag name' and 'missing tagger entry' warnings can now be
upgraded to errors by specifying `invalidTagName` and
`missingTaggerEntry` in the receive.fsck.<msg-id> config setting.

Incidentally, the missing tagger warning is now really shown as a warning
(as opposed to being reported with the "error:" prefix, as it used to be
the case before this commit).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

fsck.c

@@ -10,6 +10,7 @@
 #include "utf8.h"
 
 #define FSCK_FATAL -1
+#define FSCK_INFO -2
 
 #define FOREACH_MSG_ID(FUNC) \
 	/* fatal errors */ \
@@ -50,15 +51,16 @@
 	FUNC(ZERO_PADDED_DATE, ERROR) \
 	/* warnings */ \
 	FUNC(BAD_FILEMODE, WARN) \
-	FUNC(BAD_TAG_NAME, WARN) \
 	FUNC(EMPTY_NAME, WARN) \
 	FUNC(FULL_PATHNAME, WARN) \
 	FUNC(HAS_DOT, WARN) \
 	FUNC(HAS_DOTDOT, WARN) \
 	FUNC(HAS_DOTGIT, WARN) \
-	FUNC(MISSING_TAGGER_ENTRY, WARN) \
 	FUNC(NULL_SHA1, WARN) \
-	FUNC(ZERO_PADDED_FILEMODE, WARN)
+	FUNC(ZERO_PADDED_FILEMODE, WARN) \
+	/* infos (reported as warnings, but ignored by default) */ \
+	FUNC(BAD_TAG_NAME, INFO) \
+	FUNC(MISSING_TAGGER_ENTRY, INFO)
 
 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
 enum fsck_msg_id {
@@ -229,6 +231,8 @@ static int report(struct fsck_options *options, struct object *object,
 
 	if (msg_type == FSCK_FATAL)
 		msg_type = FSCK_ERROR;
+	else if (msg_type == FSCK_INFO)
+		msg_type = FSCK_WARN;
 
 	append_msg_id(&sb, msg_id_info[id].id_string);
 
@@ -687,15 +691,21 @@ static int fsck_tag_buffer(struct tag *tag, const char *data,
 		goto done;
 	}
 	strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
-	if (check_refname_format(sb.buf, 0))
-		report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
+	if (check_refname_format(sb.buf, 0)) {
+		ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 			   "invalid 'tag' name: %.*s",
 			   (int)(eol - buffer), buffer);
+		if (ret)
+			goto done;
+	}
 	buffer = eol + 1;
 
-	if (!skip_prefix(buffer, "tagger ", &buffer))
+	if (!skip_prefix(buffer, "tagger ", &buffer)) {
 		/* early tags do not contain 'tagger' lines; warn only */
-		report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
+		ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
+		if (ret)
+			goto done;
+	}
 	else
 		ret = fsck_ident(&buffer, &tag->object, options);
 

t/t5302-pack-index.sh

@@ -259,7 +259,7 @@ EOF
     thirtyeight=${tag#??} &&
     rm -f .git/objects/${tag%$thirtyeight}/$thirtyeight &&
     git index-pack --strict tag-test-${pack1}.pack 2>err &&
-    grep "^error:.* expected .tagger. line" err
+    grep "^warning:.* expected .tagger. line" err
 '
 
 test_done