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

@@ -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;

@@ -162,31 +191,19 @@ 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;
 }

@@ -194,24 +211,24 @@ static int fsck_tree(struct tree *item)
 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);
 	}
 
 	/*