[PATCH] Make the git-fsck-objects diagnostics more useful

Actually report what exactly is wrong with the object, instead of an
ambiguous 'bad sha1 file' or such. In places where we already do, unify
the format and clean the messages up.

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

fsck-objects.c

@@ -20,6 +20,35 @@ static int check_strict = 0;
 static int keep_cache_objects = 0; 
 static unsigned char head_sha1[20];
 
+
+static void objreport(struct object *obj, const char *severity,
+                      const char *err, va_list params)
+{
+	fprintf(stderr, "%s in %s %s: ",
+	        severity, obj->type, sha1_to_hex(obj->sha1));
+	vfprintf(stderr, err, params);
+	fputs("\n", stderr);
+}
+
+int objerror(struct object *obj, const char *err, ...)
+{
+	va_list params;
+	va_start(params, err);
+	objreport(obj, "error", err, params);
+	va_end(params);
+	return -1;
+}
+
+int objwarning(struct object *obj, const char *err, ...)
+{
+	va_list params;
+	va_start(params, err);
+	objreport(obj, "warning", err, params);
+	va_end(params);
+	return -1;
+}
+
+
 static void check_connectivity(void)
 {
 	int i;
@@ -162,56 +191,44 @@ static int fsck_tree(struct tree *item)
 
 	retval = 0;
 	if (has_full_path) {
-		fprintf(stderr, "warning: git-fsck-objects: tree %s "
-			"has full pathnames in it\n", 
-			sha1_to_hex(item->object.sha1));
+		objwarning(&item->object, "contains full pathnames");
 	}
 	if (has_zero_pad) {
-		fprintf(stderr, "warning: git-fsck-objects: tree %s "
-			"has zero-padded file modes in it\n",
-			sha1_to_hex(item->object.sha1));
+		objwarning(&item->object, "contains zero-padded file modes");
 	}
 	if (has_bad_modes) {
-		fprintf(stderr, "warning: git-fsck-objects: tree %s "
-			"has bad file modes in it\n",
-			sha1_to_hex(item->object.sha1));
+		objwarning(&item->object, "contains bad file modes");
 	}
 	if (has_dup_entries) {
-		fprintf(stderr, "error: git-fsck-objects: tree %s "
-			"has duplicate file entries\n",
-			sha1_to_hex(item->object.sha1));
-		retval = -1;
+		retval = objerror(&item->object, "contains duplicate file entries");
 	}
 	if (not_properly_sorted) {
-		fprintf(stderr, "error: git-fsck-objects: tree %s "
-			"is not properly sorted\n",
-			sha1_to_hex(item->object.sha1));
-		retval = -1;
+		retval = objerror(&item->object, "not properly sorted");
 	}
 	return retval;
 }
 
 static int fsck_commit(struct commit *commit)
 {
 	char *buffer = commit->buffer;
-	unsigned char sha1[20];
+	unsigned char tree_sha1[20], sha1[20];
 
 	if (memcmp(buffer, "tree ", 5))
-		return -1;
-	if (get_sha1_hex(buffer+5, sha1) || buffer[45] != '\n')
-		return -1;
+		return objerror(&commit->object, "invalid format - expected 'tree' line");
+	if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
+		return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
 	buffer += 46;
 	while (!memcmp(buffer, "parent ", 7)) {
 		if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
-			return -1;
+			return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
 		buffer += 48;
 	}
 	if (memcmp(buffer, "author ", 7))
-		return -1;
+		return objerror(&commit->object, "invalid format - expected 'author' line");
 	free(commit->buffer);
 	commit->buffer = NULL;
 	if (!commit->tree)
-		return -1;
+		return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
 	if (!commit->parents && show_root)
 		printf("root %s\n", sha1_to_hex(commit->object.sha1));
 	if (!commit->date)
@@ -225,8 +242,7 @@ static int fsck_tag(struct tag *tag)
 	struct object *tagged = tag->tagged;
 
 	if (!tagged) {
-		printf("bad object in tag %s\n", sha1_to_hex(tag->object.sha1));
-		return -1;
+		return objerror(&tag->object, "could not load tagged object");
 	}
 	if (!show_tags)
 		return 0;
@@ -240,7 +256,7 @@ static int fsck_sha1(unsigned char *sha1)
 {
 	struct object *obj = parse_object(sha1);
 	if (!obj)
-		return -1;
+		return error("%s: object not found", sha1_to_hex(sha1));
 	if (obj->type == blob_type)
 		return 0;
 	if (obj->type == tree_type)
@@ -249,7 +265,8 @@ static int fsck_sha1(unsigned char *sha1)
 		return fsck_commit((struct commit *) obj);
 	if (obj->type == tag_type)
 		return fsck_tag((struct tag *) obj);
-	return -1;
+	/* By now, parse_object() would've returned NULL instead. */
+	return objerror(obj, "unknown type '%s' (internal fsck error)", obj->type);
 }
 
 /*
@@ -285,8 +302,7 @@ static void fsck_sha1_list(void)
 		unsigned char *sha1 = entry->sha1;
 
 		sha1_list.entry[i] = NULL;
-		if (fsck_sha1(sha1) < 0)
-			fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(sha1));
+		fsck_sha1(sha1);
 		free(entry);
 	}
 	sha1_list.nr = 0;
@@ -479,9 +495,7 @@ int main(int argc, char **argv)
 			for (i = 0; i < num; i++) {
 				unsigned char sha1[20];
 				nth_packed_object_sha1(p, i, sha1);
-				if (fsck_sha1(sha1) < 0)
-					fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(sha1));
-
+				fsck_sha1(sha1);
 			}
 		}
 	}
@@ -505,7 +519,7 @@ int main(int argc, char **argv)
 			heads++;
 			continue;
 		}
-		error("expected sha1, got %s", arg);
+		error("invalid parameter: expected sha1, got '%s'", arg);
 	}
 
 	/*