Merge branch 'mk/maint-parse-careful'

* mk/maint-parse-careful:
  receive-pack: use strict mode for unpacking objects
  index-pack: introduce checking mode
  unpack-objects: prevent writing of inconsistent objects
  unpack-object: cache for non written objects
  add common fsck error printing function
  builtin-fsck: move common object checking code to fsck.c
  builtin-fsck: reports missing parent commits
  Remove unused object-ref code
  builtin-fsck: move away from object-refs to fsck_walk
  add generic, type aware object chain walker

Conflicts:

	Makefile
	builtin-fsck.c

1 files changed, 104 insertions, 237 deletions

diff --git a/builtin-fsck.c b/builtin-fsck.c
index cc7524be80..78a6e1ff71 100644
--- a/builtin-fsck.c
+++ b/builtin-fsck.c
@@ -8,6 +8,7 @@
 #include "pack.h"
 #include "cache-tree.h"
 #include "tree-walk.h"
+#include "fsck.h"
 #include "parse-options.h"
 
 #define REACHABLE 0x0001
@@ -54,13 +55,75 @@ static int objerror(struct object *obj, const char *err, ...)
 	return -1;
 }
 
-static int objwarning(struct object *obj, const char *err, ...)
+static int fsck_error_func(struct object *obj, int type, const char *err, ...)
 {
 	va_list params;
 	va_start(params, err);
-	objreport(obj, "warning", err, params);
+	objreport(obj, (type == FSCK_WARN) ? "warning" : "error", err, params);
 	va_end(params);
-	return -1;
+	return (type == FSCK_WARN) ? 0 : 1;
+}
+
+static int mark_object(struct object *obj, int type, void *data)
+{
+	struct tree *tree = NULL;
+	struct object *parent = data;
+	int result;
+
+	if (!obj) {
+		printf("broken link from %7s %s\n",
+			   typename(parent->type), sha1_to_hex(parent->sha1));
+		printf("broken link from %7s %s\n",
+			   (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
+		errors_found |= ERROR_REACHABLE;
+		return 1;
+	}
+
+	if (type != OBJ_ANY && obj->type != type)
+		objerror(parent, "wrong object type in link");
+
+	if (obj->flags & REACHABLE)
+		return 0;
+	obj->flags |= REACHABLE;
+	if (!obj->parsed) {
+		if (parent && !has_sha1_file(obj->sha1)) {
+			printf("broken link from %7s %s\n",
+				 typename(parent->type), sha1_to_hex(parent->sha1));
+			printf("              to %7s %s\n",
+				 typename(obj->type), sha1_to_hex(obj->sha1));
+			errors_found |= ERROR_REACHABLE;
+		}
+		return 1;
+	}
+
+	if (obj->type == OBJ_TREE) {
+		obj->parsed = 0;
+		tree = (struct tree *)obj;
+		if (parse_tree(tree) < 0)
+			return 1; /* error already displayed */
+	}
+	result = fsck_walk(obj, mark_object, obj);
+	if (tree) {
+		free(tree->buffer);
+		tree->buffer = NULL;
+	}
+	if (result < 0)
+		result = 1;
+
+	return result;
+}
+
+static void mark_object_reachable(struct object *obj)
+{
+	mark_object(obj, OBJ_ANY, 0);
+}
+
+static int mark_used(struct object *obj, int type, void *data)
+{
+	if (!obj)
+		return 1;
+	obj->used = 1;
+	return 0;
 }
 
 /*
@@ -68,8 +131,6 @@ static int objwarning(struct object *obj, const char *err, ...)
  */
 static void check_reachable_object(struct object *obj)
 {
-	const struct object_refs *refs;
-
 	/*
 	 * We obviously want the object to be parsed,
 	 * except if it was in a pack-file and we didn't
@@ -82,25 +143,6 @@ static void check_reachable_object(struct object *obj)
 		errors_found |= ERROR_REACHABLE;
 		return;
 	}
-
-	/*
-	 * Check that everything that we try to reference is also good.
-	 */
-	refs = lookup_object_refs(obj);
-	if (refs) {
-		unsigned j;
-		for (j = 0; j < refs->count; j++) {
-			struct object *ref = refs->ref[j];
-			if (ref->parsed ||
-			    (has_sha1_file(ref->sha1)))
-				continue;
-			printf("broken link from %7s %s\n",
-			       typename(obj->type), sha1_to_hex(obj->sha1));
-			printf("              to %7s %s\n",
-			       typename(ref->type), sha1_to_hex(ref->sha1));
-			errors_found |= ERROR_REACHABLE;
-		}
-	}
 }
 
 /*
@@ -204,230 +246,56 @@ static void check_connectivity(void)
 	}
 }
 
-/*
- * The entries in a tree are ordered in the _path_ order,
- * which means that a directory entry is ordered by adding
- * a slash to the end of it.
- *
- * So a directory called "a" is ordered _after_ a file
- * called "a.c", because "a/" sorts after "a.c".
- */
-#define TREE_UNORDERED (-1)
-#define TREE_HAS_DUPS  (-2)
-
-static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
+static int fsck_sha1(const unsigned char *sha1)
 {
-	int len1 = strlen(name1);
-	int len2 = strlen(name2);
-	int len = len1 < len2 ? len1 : len2;
-	unsigned char c1, c2;
-	int cmp;
-
-	cmp = memcmp(name1, name2, len);
-	if (cmp < 0)
+	struct object *obj = parse_object(sha1);
+	if (!obj) {
+		errors_found |= ERROR_OBJECT;
+		return error("%s: object corrupt or missing",
+			     sha1_to_hex(sha1));
+	}
+	if (obj->flags & SEEN)
 		return 0;
-	if (cmp > 0)
-		return TREE_UNORDERED;
-
-	/*
-	 * Ok, the first <len> characters are the same.
-	 * Now we need to order the next one, but turn
-	 * a '\0' into a '/' for a directory entry.
-	 */
-	c1 = name1[len];
-	c2 = name2[len];
-	if (!c1 && !c2)
-		/*
-		 * git-write-tree used to write out a nonsense tree that has
-		 * entries with the same name, one blob and one tree.  Make
-		 * sure we do not have duplicate entries.
-		 */
-		return TREE_HAS_DUPS;
-	if (!c1 && S_ISDIR(mode1))
-		c1 = '/';
-	if (!c2 && S_ISDIR(mode2))
-		c2 = '/';
-	return c1 < c2 ? 0 : TREE_UNORDERED;
-}
-
-static int fsck_tree(struct tree *item)
-{
-	int retval;
-	int has_full_path = 0;
-	int has_empty_name = 0;
-	int has_zero_pad = 0;
-	int has_bad_modes = 0;
-	int has_dup_entries = 0;
-	int not_properly_sorted = 0;
-	struct tree_desc desc;
-	unsigned o_mode;
-	const char *o_name;
-	const unsigned char *o_sha1;
+	obj->flags |= SEEN;
 
 	if (verbose)
-		fprintf(stderr, "Checking tree %s\n",
-				sha1_to_hex(item->object.sha1));
-
-	init_tree_desc(&desc, item->buffer, item->size);
-
-	o_mode = 0;
-	o_name = NULL;
-	o_sha1 = NULL;
-	while (desc.size) {
-		unsigned mode;
-		const char *name;
-		const unsigned char *sha1;
-
-		sha1 = tree_entry_extract(&desc, &name, &mode);
-
-		if (strchr(name, '/'))
-			has_full_path = 1;
-		if (!*name)
-			has_empty_name = 1;
-		has_zero_pad |= *(char *)desc.buffer == '0';
-		update_tree_entry(&desc);
-
-		switch (mode) {
-		/*
-		 * Standard modes..
-		 */
-		case S_IFREG | 0755:
-		case S_IFREG | 0644:
-		case S_IFLNK:
-		case S_IFDIR:
-		case S_IFGITLINK:
-			break;
-		/*
-		 * This is nonstandard, but we had a few of these
-		 * early on when we honored the full set of mode
-		 * bits..
-		 */
-		case S_IFREG | 0664:
-			if (!check_strict)
-				break;
-		default:
-			has_bad_modes = 1;
-		}
+		fprintf(stderr, "Checking %s %s\n",
+			typename(obj->type), sha1_to_hex(obj->sha1));
 
-		if (o_name) {
-			switch (verify_ordered(o_mode, o_name, mode, name)) {
-			case TREE_UNORDERED:
-				not_properly_sorted = 1;
-				break;
-			case TREE_HAS_DUPS:
-				has_dup_entries = 1;
-				break;
-			default:
-				break;
-			}
-		}
+	if (fsck_walk(obj, mark_used, 0))
+		objerror(obj, "broken links");
+	if (fsck_object(obj, check_strict, fsck_error_func))
+		return -1;
 
-		o_mode = mode;
-		o_name = name;
-		o_sha1 = sha1;
-	}
-	free(item->buffer);
-	item->buffer = NULL;
+	if (obj->type == OBJ_TREE) {
+		struct tree *item = (struct tree *) obj;
 
-	retval = 0;
-	if (has_full_path) {
-		objwarning(&item->object, "contains full pathnames");
+		free(item->buffer);
+		item->buffer = NULL;
 	}
-	if (has_empty_name) {
-		objwarning(&item->object, "contains empty pathname");
-	}
-	if (has_zero_pad) {
-		objwarning(&item->object, "contains zero-padded file modes");
-	}
-	if (has_bad_modes) {
-		objwarning(&item->object, "contains bad file modes");
-	}
-	if (has_dup_entries) {
-		retval = objerror(&item->object, "contains duplicate file entries");
-	}
-	if (not_properly_sorted) {
-		retval = objerror(&item->object, "not properly sorted");
-	}
-	return retval;
-}
 
-static int fsck_commit(struct commit *commit)
-{
-	char *buffer = commit->buffer;
-	unsigned char tree_sha1[20], sha1[20];
+	if (obj->type == OBJ_COMMIT) {
+		struct commit *commit = (struct commit *) obj;
 
-	if (verbose)
-		fprintf(stderr, "Checking commit %s\n",
-			sha1_to_hex(commit->object.sha1));
-
-	if (!commit->date)
-		return objerror(&commit->object, "invalid author/committer line");
-
-	if (memcmp(buffer, "tree ", 5))
-		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 objerror(&commit->object, "invalid 'parent' line format - bad sha1");
-		buffer += 48;
-	}
-	if (memcmp(buffer, "author ", 7))
-		return objerror(&commit->object, "invalid format - expected 'author' line");
-	free(commit->buffer);
-	commit->buffer = NULL;
-	if (!commit->tree)
-		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));
-	return 0;
-}
+		free(commit->buffer);
+		commit->buffer = NULL;
 
-static int fsck_tag(struct tag *tag)
-{
-	struct object *tagged = tag->tagged;
+		if (!commit->parents && show_root)
+			printf("root %s\n", sha1_to_hex(commit->object.sha1));
+	}
 
-	if (verbose)
-		fprintf(stderr, "Checking tag %s\n",
-			sha1_to_hex(tag->object.sha1));
+	if (obj->type == OBJ_TAG) {
+		struct tag *tag = (struct tag *) obj;
 
-	if (!tagged) {
-		return objerror(&tag->object, "could not load tagged object");
+		if (show_tags && tag->tagged) {
+			printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
+			printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
+		}
 	}
-	if (!show_tags)
-		return 0;
 
-	printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
-	printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
 	return 0;
 }
 
-static int fsck_sha1(const unsigned char *sha1)
-{
-	struct object *obj = parse_object(sha1);
-	if (!obj) {
-		errors_found |= ERROR_OBJECT;
-		return error("%s: object corrupt or missing",
-			     sha1_to_hex(sha1));
-	}
-	if (obj->flags & SEEN)
-		return 0;
-	obj->flags |= SEEN;
-	if (obj->type == OBJ_BLOB)
-		return 0;
-	if (obj->type == OBJ_TREE)
-		return fsck_tree((struct tree *) obj);
-	if (obj->type == OBJ_COMMIT)
-		return fsck_commit((struct commit *) obj);
-	if (obj->type == OBJ_TAG)
-		return fsck_tag((struct tag *) obj);
-
-	/* By now, parse_object() would've returned NULL instead. */
-	return objerror(obj, "unknown type '%d' (internal fsck error)",
-			obj->type);
-}
-
 /*
  * This is the sorting chunk size: make it reasonably
  * big so that we can sort well..
@@ -538,13 +406,13 @@ static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 		obj = lookup_object(osha1);
 		if (obj) {
 			obj->used = 1;
-			mark_reachable(obj, REACHABLE);
+			mark_object_reachable(obj);
 		}
 	}
 	obj = lookup_object(nsha1);
 	if (obj) {
 		obj->used = 1;
-		mark_reachable(obj, REACHABLE);
+		mark_object_reachable(obj);
 	}
 	return 0;
 }
@@ -574,7 +442,7 @@ static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int f
 		error("%s: not a commit", refname);
 	default_refs++;
 	obj->used = 1;
-	mark_reachable(obj, REACHABLE);
+	mark_object_reachable(obj);
 
 	return 0;
 }
@@ -660,7 +528,7 @@ static int fsck_cache_tree(struct cache_tree *it)
 			      sha1_to_hex(it->sha1));
 			return 1;
 		}
-		mark_reachable(obj, REACHABLE);
+		mark_object_reachable(obj);
 		obj->used = 1;
 		if (obj->type != OBJ_TREE)
 			err |= objerror(obj, "non-tree in cache-tree");
@@ -693,7 +561,6 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 {
 	int i, heads;
 
-	track_object_refs = 1;
 	errors_found = 0;
 
 	argc = parse_options(argc, argv, fsck_opts, fsck_usage, 0);
@@ -741,7 +608,7 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 				continue;
 
 			obj->used = 1;
-			mark_reachable(obj, REACHABLE);
+			mark_object_reachable(obj);
 			heads++;
 			continue;
 		}
@@ -773,7 +640,7 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 				continue;
 			obj = &blob->object;
 			obj->used = 1;
-			mark_reachable(obj, REACHABLE);
+			mark_object_reachable(obj);
 		}
 		if (active_cache_tree)
 			fsck_cache_tree(active_cache_tree);