Don't dereference NULL upon lookup failure.

Instead, signal the error just like the case we do upon encountering
an object with an unknown type.

Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/object.c b/object.c
index 16793d9958a57664233b9e4468e112dfa1a8a915..5a5ebe27b0db0506dc1a6606d30e328c53275c18 100644 (file)
--- a/object.c
+++ b/object.c
@@ -136,29 +136,38 @@ struct object *parse_object_buffer(const unsigned char *sha1, enum object_type t
        struct object *obj;
        int eaten = 0;
 
+       obj = NULL;
        if (type == OBJ_BLOB) {
                struct blob *blob = lookup_blob(sha1);
-               parse_blob_buffer(blob, buffer, size);
-               obj = &blob->object;
+               if (blob) {
+                       parse_blob_buffer(blob, buffer, size);
+                       obj = &blob->object;
+               }
        } else if (type == OBJ_TREE) {
                struct tree *tree = lookup_tree(sha1);
-               obj = &tree->object;
-               if (!tree->object.parsed) {
-                       parse_tree_buffer(tree, buffer, size);
-                       eaten = 1;
+               if (tree) {
+                       obj = &tree->object;
+                       if (!tree->object.parsed) {
+                               parse_tree_buffer(tree, buffer, size);
+                               eaten = 1;
+                       }
                }
        } else if (type == OBJ_COMMIT) {
                struct commit *commit = lookup_commit(sha1);
-               parse_commit_buffer(commit, buffer, size);
-               if (!commit->buffer) {
-                       commit->buffer = buffer;
-                       eaten = 1;
+               if (commit) {
+                       parse_commit_buffer(commit, buffer, size);
+                       if (!commit->buffer) {
+                               commit->buffer = buffer;
+                               eaten = 1;
+                       }
+                       obj = &commit->object;
                }
-               obj = &commit->object;
        } else if (type == OBJ_TAG) {
                struct tag *tag = lookup_tag(sha1);
-               parse_tag_buffer(tag, buffer, size);
-               obj = &tag->object;
+               if (tag) {
+                       parse_tag_buffer(tag, buffer, size);
+                       obj = &tag->object;
+               }
        } else {
                warning("object %s has unknown type id %d\n", sha1_to_hex(sha1), type);
                obj = NULL;