git-convert-cache: fix up mode conversion

The old mode conversion was not only complex, it also refused to change
the length of a mode, which made it fragile.  By moving the mode
conversion around a bit, we can not only simplify it, it also ends up
being more powerful.

Also fix a memory leak that made it impossible to convert huge archives
without tons and tons of memory.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/convert-cache.c b/convert-cache.c
index ee599f1..8916a36 100644 (file)
--- a/convert-cache.c
+++ b/convert-cache.c
@@ -60,11 +60,21 @@ static void convert_ascii_sha1(void *buffer)
        struct entry *entry;
 
        if (get_sha1_hex(buffer, sha1))
-               die("bad sha1");
+               die("expected sha1, got '%s'", buffer);
        entry = convert_entry(sha1);
        memcpy(buffer, sha1_to_hex(entry->new_sha1), 40);
 }
 
+static unsigned int convert_mode(unsigned int mode)
+{
+       unsigned int newmode;
+
+       newmode = mode & S_IFMT;
+       if (S_ISREG(mode))
+               newmode |= (mode & 0100) ? 0755 : 0644;
+       return newmode;
+}
+
 static int write_subdirectory(void *buffer, unsigned long size, const char *base, int baselen, unsigned char *result_sha1)
 {
        char *new = xmalloc(size);
@@ -81,6 +91,7 @@ static int write_subdirectory(void *buffer, unsigned long size, const char *base
 
                if (!path || sscanf(buffer, "%o", &mode) != 1)
                        die("bad tree conversion");
+               mode = convert_mode(mode);
                path++;
                if (memcmp(path, base, baselen))
                        break;
@@ -116,34 +127,6 @@ static int write_subdirectory(void *buffer, unsigned long size, const char *base
        return used;
 }
 
-static int convert_mode(char *buffer)
-{
-       char *end;
-       unsigned short mode = strtoul(buffer, &end, 8);
-       unsigned short newmode;
-       char num[10];
-       int len;
-
-       if (*end != ' ')
-               die("corrupt tree object");
-       switch (mode) {
-       case S_IFREG | 0644:
-       case S_IFREG | 0755:
-       case S_IFLNK:
-       case S_IFDIR:
-               return 0;
-       }
-       newmode = 0;
-       if (S_ISREG(mode))
-               newmode = (mode & 0100) ? 0755 : 0644;
-       newmode |= mode & S_IFMT;
-       len = sprintf(num, "%o", newmode);
-       if (len != end - buffer)
-               return error("unable to convert tree entry mode %o to %o", mode, newmode);
-       memcpy(buffer, num, len);
-       return 0;
-}
-
 static void convert_tree(void *buffer, unsigned long size, unsigned char *result_sha1)
 {
        void *orig_buffer = buffer;
@@ -152,7 +135,6 @@ static void convert_tree(void *buffer, unsigned long size, unsigned char *result
        while (size) {
                int len = 1+strlen(buffer);
 
-               convert_mode(buffer);
                convert_binary_sha1(buffer + len);
 
                len += 20;
@@ -289,6 +271,8 @@ static void convert_commit(void *buffer, unsigned long size, unsigned char *resu
        void *orig_buffer = buffer;
        unsigned long orig_size = size;
 
+       if (memcmp(buffer, "tree ", 5))
+               die("Bad commit '%s'", buffer);
        convert_ascii_sha1(buffer+5);
        buffer += 46;    /* "tree " + "hex sha1" + "\n" */
        while (!memcmp(buffer, "parent ", 7)) {
@@ -324,6 +308,7 @@ static struct entry * convert_entry(unsigned char *sha1)
                die("unknown object type '%s' in %s", type, sha1_to_hex(sha1));
        entry->converted = 1;
        free(buffer);
+       free(data);
        return entry;
 }