git-remote-testgit: fix race when spawning fast-import

diff --git a/sha1_file.c b/sha1_file.c
index 61e51edc42535689072e9919f1ffcc79be8f2bad..4f06a0e450359744528d3b125fb09eacebf1eb4a 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -54,6 +54,8 @@ static struct cached_object empty_tree = {
        0
 };
 
+static struct packed_git *last_found_pack;
+
 static struct cached_object *find_cached_object(const unsigned char *sha1)
 {
        int i;
@@ -720,6 +722,8 @@ void free_pack_by_name(const char *pack_name)
                        close_pack_index(p);
                        free(p->bad_object_sha1);
                        *pp = p->next;
+                       if (last_found_pack == p)
+                               last_found_pack = NULL;
                        free(p);
                        return;
                }
@@ -1202,6 +1206,11 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 
                if (!fstat(fd, &st)) {
                        *size = xsize_t(st.st_size);
+                       if (!*size) {
+                               /* mmap() is forbidden on empty files */
+                               error("object file %s is empty", sha1_file_name(sha1));
+                               return NULL;
+                       }
                        map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
                }
                close(fd);
@@ -2046,27 +2055,22 @@ static int fill_pack_entry(const unsigned char *sha1,
 
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 {
-       static struct packed_git *last_found = (void *)1;
        struct packed_git *p;
 
        prepare_packed_git();
        if (!packed_git)
                return 0;
-       p = (last_found == (void *)1) ? packed_git : last_found;
 
-       do {
-               if (fill_pack_entry(sha1, e, p)) {
-                       last_found = p;
-                       return 1;
-               }
+       if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
+               return 1;
 
-               if (p == last_found)
-                       p = packed_git;
-               else
-                       p = p->next;
-               if (p == last_found)
-                       p = p->next;
-       } while (p);
+       for (p = packed_git; p; p = p->next) {
+               if (p == last_found_pack || !fill_pack_entry(sha1, e, p))
+                       continue;
+
+               last_found_pack = p;
+               return 1;
+       }
        return 0;
 }
 
@@ -2696,10 +2700,13 @@ static int index_core(unsigned char *sha1, int fd, size_t size,
  * This also bypasses the usual "convert-to-git" dance, and that is on
  * purpose. We could write a streaming version of the converting
  * functions and insert that before feeding the data to fast-import
- * (or equivalent in-core API described above), but the primary
- * motivation for trying to stream from the working tree file and to
- * avoid mmaping it in core is to deal with large binary blobs, and
- * by definition they do _not_ want to get any conversion.
+ * (or equivalent in-core API described above). However, that is
+ * somewhat complicated, as we do not know the size of the filter
+ * result, which we need to know beforehand when writing a git object.
+ * Since the primary motivation for trying to stream from the working
+ * tree file and to avoid mmaping it in core is to deal with large
+ * binary blobs, they generally do not want to get any conversion, and
+ * callers should avoid this code path when filters are requested.
  */
 static int index_stream(unsigned char *sha1, int fd, size_t size,
                        enum object_type type, const char *path,
@@ -2716,7 +2723,8 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st,
 
        if (!S_ISREG(st->st_mode))
                ret = index_pipe(sha1, fd, type, path, flags);
-       else if (size <= big_file_threshold || type != OBJ_BLOB)
+       else if (size <= big_file_threshold || type != OBJ_BLOB ||
+                (path && would_convert_to_git(path, NULL, 0, 0)))
                ret = index_core(sha1, fd, size, type, path, flags);
        else
                ret = index_stream(sha1, fd, size, type, path, flags);