fast-import: do not call diff_delta() with empty buffer

diff --git a/commit.h b/commit.h
index e57ae4b58380cce6192cc6489682838677f048ce..3ad07c2e3d092a97e3bc20091566f4b967b6bc8c 100644 (file)
--- a/commit.h
+++ b/commit.h
@@ -10,20 +10,34 @@
 #include "pretty.h"
 
 #define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
+#define GENERATION_NUMBER_INFINITY 0xFFFFFFFF
+#define GENERATION_NUMBER_MAX 0x3FFFFFFF
+#define GENERATION_NUMBER_ZERO 0
 
 struct commit_list {
        struct commit *item;
        struct commit_list *next;
 };
 
+/*
+ * The size of this struct matters in full repo walk operations like
+ * 'git clone' or 'git gc'. Consider using commit-slab to attach data
+ * to a commit instead of adding new fields here.
+ */
 struct commit {
        struct object object;
-       void *util;
-       unsigned int index;
        timestamp_t date;
        struct commit_list *parents;
-       struct tree *tree;
+
+       /*
+        * If the commit is loaded from the commit-graph file, then this
+        * member may be NULL. Only access it through get_commit_tree()
+        * or get_commit_tree_oid().
+        */
+       struct tree *maybe_tree;
        uint32_t graph_pos;
+       uint32_t generation;
+       unsigned int index;
 };
 
 extern int save_commit_buffer;
@@ -62,7 +76,7 @@ struct commit *lookup_commit_reference_by_name(const char *name);
  */
 struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name);
 
-int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size);
+int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size, int check_graph);
 int parse_commit_gently(struct commit *item, int quiet_on_missing);
 static inline int parse_commit(struct commit *item)
 {
@@ -102,6 +116,15 @@ void unuse_commit_buffer(const struct commit *, const void *buffer);
  */
 void free_commit_buffer(struct commit *);
 
+struct tree *get_commit_tree(const struct commit *);
+struct object_id *get_commit_tree_oid(const struct commit *);
+
+/*
+ * Release memory related to a commit, including the parent list and
+ * any cached object buffer.
+ */
+void release_commit_memory(struct commit *c);
+
 /*
  * Disassociate any cached object buffer from the commit, but do not free it.
  * The buffer (or NULL, if none) is returned.
@@ -294,16 +317,16 @@ extern const char *find_commit_header(const char *msg, const char *key,
 /* Find the end of the log message, the right place for a new trailer. */
 extern int ignore_non_trailer(const char *buf, size_t len);
 
-typedef void (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
+typedef int (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
                                 void *cb_data);
 
-extern void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
+extern int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
 
 struct merge_remote_desc {
        struct object *obj; /* the named object, could be a tag */
        char name[FLEX_ARRAY];
 };
-#define merge_remote_util(commit) ((struct merge_remote_desc *)((commit)->util))
+extern struct merge_remote_desc *merge_remote_util(struct commit *);
 extern void set_merge_remote_desc(struct commit *commit,
                                  const char *name, struct object *obj);
 
@@ -328,6 +351,7 @@ extern int remove_signature(struct strbuf *buf);
 extern int check_commit_signature(const struct commit *commit, struct signature_check *sigc);
 
 int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused);
+int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused);
 
 LAST_ARG_MUST_BE_NULL
 extern int run_commit_hook(int editor_is_used, const char *index_file, const char *name, ...);