X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=read-tree.c;h=3746984125026d608493e407c1ef3cc98c007a71;hb=76f38347b4199f65e8c897ebf4f9ce1d3a24378b;hp=53351f05c74cb892530c2d351592cc0cc1a1274c;hpb=c5bac17ad21c8e79fcca21c366832e75be095322;p=git.git

diff --git a/read-tree.c b/read-tree.c
index 53351f05..37469841 100644
--- a/read-tree.c
+++ b/read-tree.c
@@ -7,84 +7,26 @@
 
 static int stage = 0;
 
-static int read_one_entry(unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode)
-{
-	int len = strlen(pathname);
-	unsigned int size = cache_entry_size(baselen + len);
-	struct cache_entry *ce = malloc(size);
-
-	memset(ce, 0, size);
-
-	ce->ce_mode = create_ce_mode(mode);
-	ce->ce_flags = create_ce_flags(baselen + len, stage);
-	memcpy(ce->name, base, baselen);
-	memcpy(ce->name + baselen, pathname, len+1);
-	memcpy(ce->sha1, sha1, 20);
-	return add_cache_entry(ce, 1);
-}
-
-static int read_tree_recursive(void *buffer, const char *type,
-			       unsigned long size,
-			       const char *base, int baselen)
-{
-	if (!buffer || strcmp(type, "tree"))
-		return -1;
-	while (size) {
-		int len = strlen(buffer)+1;
-		unsigned char *sha1 = buffer + len;
-		char *path = strchr(buffer, ' ')+1;
-		unsigned int mode;
-
-		if (size < len + 20 || sscanf(buffer, "%o", &mode) != 1)
-			return -1;
-
-		buffer = sha1 + 20;
-		size -= len + 20;
-
-		if (S_ISDIR(mode)) {
-			int retval;
-			int pathlen = strlen(path);
-			char *newbase = malloc(baselen + 1 + pathlen);
-			void *eltbuf;
-			char elttype[20];
-			unsigned long eltsize;
-
-			eltbuf = read_sha1_file(sha1, elttype, &eltsize);
-			if (!eltbuf)
-				return -1;
-			memcpy(newbase, base, baselen);
-			memcpy(newbase + baselen, path, pathlen);
-			newbase[baselen + pathlen] = '/';
-			retval = read_tree_recursive(eltbuf, elttype, eltsize,
-						     newbase,
-						     baselen + pathlen + 1);
-			free(eltbuf);
-			free(newbase);
-			if (retval)
-				return -1;
-			continue;
-		}
-		if (read_one_entry(sha1, base, baselen, path, mode) < 0)
-			return -1;
-	}
-	return 0;
-}
-
-static int read_tree(unsigned char *sha1, const char *base, int baselen)
+static int unpack_tree(unsigned char *sha1)
 {
 	void *buffer;
 	unsigned long size;
+	int ret;
 
-	buffer = read_tree_with_tree_or_commit_sha1(sha1, &size, 0);
-	return read_tree_recursive(buffer, "tree", size, base, baselen);
+	buffer = read_object_with_reference(sha1, "tree", &size, NULL);
+	if (!buffer)
+		return -1;
+	ret = read_tree(buffer, size, stage);
+	free(buffer);
+	return ret;
 }
 
-static int remove_lock = 0;
+static char *lockfile_name;
 
 static void remove_lock_file(void)
 {
-	if (remove_lock)
-		unlink(".git/index.lock");
+	if (lockfile_name)
+		unlink(lockfile_name);
 }
 
 static int path_matches(struct cache_entry *a, struct cache_entry *b)
@@ -151,11 +93,42 @@ static struct cache_entry *merge_entries(struct cache_entry *a,
 	return NULL;
 }
 
+/*
+ * When a CE gets turned into an unmerged entry, we
+ * want it to be up-to-date
+ */
+static void verify_uptodate(struct cache_entry *ce)
+{
+	struct stat st;
+
+	if (!lstat(ce->name, &st)) {
+		unsigned changed = ce_match_stat(ce, &st);
+		if (!changed)
+			return;
+		errno = 0;
+	}
+	if (errno == ENOENT)
+		return;
+	die("Entry '%s' not uptodate. Cannot merge.", ce->name);
+}
+
+/*
+ * If the old tree contained a CE that isn't even in the
+ * result, that's always a problem, regardless of whether
+ * it's up-to-date or not (ie it can be a file that we
+ * have updated but not committed yet).
+ */
+static void reject_merge(struct cache_entry *ce)
+{
+	die("Entry '%s' would be overwritten by merge. Cannot merge.", ce->name);
+}
+
+#define CHECK_OLD(ce) if (old && same(old, ce)) { verify_uptodate(old); old = NULL; }
+
 static void trivially_merge_cache(struct cache_entry **src, int nr)
 {
-	static struct cache_entry null_entry;
 	struct cache_entry **dst = src;
-	struct cache_entry *old = &null_entry;
+	struct cache_entry *old = NULL;
 
 	while (nr) {
 		struct cache_entry *ce, *result;
@@ -164,29 +137,46 @@ static void trivially_merge_cache(struct cache_entry **src, int nr)
 
 		/* We throw away original cache entries except for the stat information */
 		if (!ce_stage(ce)) {
+			if (old)
+				reject_merge(old);
 			old = ce;
 			src++;
 			nr--;
 			active_nr--;
 			continue;
 		}
+		if (old && !path_matches(old, ce))
+			reject_merge(old);
 		if (nr > 2 && (result = merge_entries(ce, src[1], src[2])) != NULL) {
 			/*
 			 * See if we can re-use the old CE directly?
 			 * That way we get the uptodate stat info.
 			 */
-			if (path_matches(result, old) && same(result, old))
+			if (old && same(old, result)) {
 				*result = *old;
+				old = NULL;
+			}
+			CHECK_OLD(ce);
+			CHECK_OLD(src[1]);
+			CHECK_OLD(src[2]);
 			ce = result;
 			ce->ce_flags &= ~htons(CE_STAGEMASK);
 			src += 2;
 			nr -= 2;
 			active_nr -= 2;
 		}
+
+		/*
+		 * If we had an old entry that we now effectively
+		 * overwrite, make sure it wasn't dirty.
+		 */
+		CHECK_OLD(ce);
 		*dst++ = ce;
 		src++;
 		nr--;
 	}
+	if (old)
+		reject_merge(old);
 }
 
 static void merge_stat_info(struct cache_entry **src, int nr)
@@ -217,18 +207,22 @@ static void merge_stat_info(struct cache_entry **src, int nr)
 	}
 }
 
-static char *read_tree_usage = "read-tree (<sha> | -m <sha1> [<sha2> <sha3>])";
+static char *read_tree_usage = "git-read-tree (<sha> | -m <sha1> [<sha2> <sha3>])";
 
 int main(int argc, char **argv)
 {
 	int i, newfd, merge;
 	unsigned char sha1[20];
+	static char lockfile[MAXPATHLEN+1];
+	const char *indexfile = get_index_file();
+
+	snprintf(lockfile, sizeof(lockfile), "%s.lock", indexfile);
 
-	newfd = open(".git/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
+	newfd = open(lockfile, O_RDWR | O_CREAT | O_EXCL, 0600);
 	if (newfd < 0)
 		die("unable to create new cachefile");
 	atexit(remove_lock_file);
-	remove_lock = 1;
+	lockfile_name = lockfile;
 
 	merge = 0;
 	for (i = 1; i < argc; i++) {
@@ -248,11 +242,11 @@ int main(int argc, char **argv)
 			merge = 1;
 			continue;
 		}
-		if (get_sha1_hex(arg, sha1) < 0)
+		if (get_sha1(arg, sha1) < 0)
 			usage(read_tree_usage);
 		if (stage > 3)
 			usage(read_tree_usage);
-		if (read_tree(sha1, "", 0) < 0)
+		if (unpack_tree(sha1) < 0)
 			die("failed to unpack tree object %s", arg);
 		stage++;
 	}
@@ -268,9 +262,8 @@ int main(int argc, char **argv)
 			die("just how do you expect me to merge %d trees?", stage-1);
 		}
 	}
-	if (write_cache(newfd, active_cache, active_nr) ||
-	    rename(".git/index.lock", ".git/index"))
+	if (write_cache(newfd, active_cache, active_nr) || rename(lockfile, indexfile))
 		die("unable to write new index file");
-	remove_lock = 0;
+	lockfile_name = NULL;
 	return 0;
 }