Ensure return value from xread() is always stored into an ssize_t

diff --git a/combine-diff.c b/combine-diff.c
index a5f2c8dd4a414e513d0421f9a499d06c73ecaf5a..ea3ca5f950561a92fdd3be1a4ee4bbd726656118 100644 (file)
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -92,14 +92,14 @@ struct sline {
 static char *grab_blob(const unsigned char *sha1, unsigned long *size)
 {
        char *blob;
-       char type[20];
+       enum object_type type;
        if (is_null_sha1(sha1)) {
                /* deleted blob */
                *size = 0;
                return xcalloc(1, 1);
        }
-       blob = read_sha1_file(sha1, type, size);
-       if (strcmp(type, blob_type))
+       blob = read_sha1_file(sha1, &type, size);
+       if (type != OBJ_BLOB)
                die("object '%s' is not a blob!", sha1_to_hex(sha1));
        return blob;
 }
@@ -678,17 +678,43 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
        else {
                /* Used by diff-tree to read from the working tree */
                struct stat st;
-               int fd;
-               if (0 <= (fd = open(elem->path, O_RDONLY)) &&
-                   !fstat(fd, &st)) {
-                       int len = st.st_size;
-                       int sz = 0;
+               int fd = -1;
 
+               if (lstat(elem->path, &st) < 0)
+                       goto deleted_file;
+
+               if (S_ISLNK(st.st_mode)) {
+                       size_t len = xsize_t(st.st_size);
+                       result_size = len;
+                       result = xmalloc(len + 1);
+                       if (result_size != readlink(elem->path, result, len)) {
+                               error("readlink(%s): %s", elem->path,
+                                     strerror(errno));
+                               return;
+                       }
+                       result[len] = 0;
                        elem->mode = canon_mode(st.st_mode);
+               }
+               else if (0 <= (fd = open(elem->path, O_RDONLY)) &&
+                        !fstat(fd, &st)) {
+                       size_t len = xsize_t(st.st_size);
+                       size_t sz = 0;
+                       int is_file, i;
+
+                       elem->mode = canon_mode(st.st_mode);
+                       /* if symlinks don't work, assume symlink if all parents
+                        * are symlinks
+                        */
+                       is_file = has_symlinks;
+                       for (i = 0; !is_file && i < num_parent; i++)
+                               is_file = !S_ISLNK(elem->parent[i].mode);
+                       if (!is_file)
+                               elem->mode = canon_mode(S_IFLNK);
+
                        result_size = len;
                        result = xmalloc(len + 1);
                        while (sz < len) {
-                               int done = xread(fd, result+sz, len-sz);
+                               ssize_t done = xread(fd, result+sz, len-sz);
                                if (done == 0)
                                        break;
                                if (done < 0)
@@ -698,11 +724,12 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
                        result[len] = 0;
                }
                else {
-                       /* deleted file */
+               deleted_file:
                        result_size = 0;
                        elem->mode = 0;
                        result = xcalloc(1, 1);
                }
+
                if (0 <= fd)
                        close(fd);
        }
@@ -916,6 +943,7 @@ void diff_tree_combined(const unsigned char *sha1,
        diffopts = *opt;
        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
        diffopts.recursive = 1;
+       diffopts.allow_external = 0;
 
        show_log_first = !!rev->loginfo && !rev->no_commit_id;
        needsep = 0;