Merge gitk changes from Paul Mackerras at git://ozlabs.org/~paulus/gitk

[git.git] / sha1_file.c

diff --git a/sha1_file.c b/sha1_file.c
index 6b1b5125c8f992927b70ce10c43f2332f5948bc0..4f06a0e450359744528d3b125fb09eacebf1eb4a 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1206,6 +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);
@@ -2695,10 +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,
@@ -2715,7 +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);