merge-recursive: enforce rule that index matches head before merging

diff --git a/cache.h b/cache.h
index d06932ed0bd049c8d41906da3508725c8978aa1c..fad10c3bfe564caec98d53d1406eacb4ad6bf35a 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -218,6 +218,7 @@ struct cache_entry {
 /* Forward structure decls */
 struct pathspec;
 struct child_process;
+struct tree;
 
 /*
  * Copy the sha1 and stat state of a cache entry from one to
@@ -599,6 +600,7 @@ extern int read_index_unmerged(struct index_state *);
 
 /* For use with `write_locked_index()`. */
 #define COMMIT_LOCK            (1 << 0)
+#define SKIP_IF_UNCHANGED      (1 << 1)
 
 /*
  * Write the index while holding an already-taken lock. Close the lock,
@@ -615,6 +617,9 @@ extern int read_index_unmerged(struct index_state *);
  * With `COMMIT_LOCK`, the lock is always committed or rolled back.
  * Without it, the lock is closed, but neither committed nor rolled
  * back.
+ *
+ * If `SKIP_IF_UNCHANGED` is given and the index is unchanged, nothing
+ * is written (and the lock is rolled back if `COMMIT_LOCK` is given).
  */
 extern int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
 
@@ -623,14 +628,17 @@ extern void move_index_extensions(struct index_state *dst, struct index_state *s
 extern int unmerged_index(const struct index_state *);
 
 /**
- * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
- * branch, returns 1 if there are entries in the index, 0 otherwise. If an
- * strbuf is provided, the space-separated list of files that differ will be
- * appended to it.
+ * Returns 1 if istate differs from tree, 0 otherwise.  If tree is NULL,
+ * compares istate to HEAD.  If tree is NULL and on an unborn branch,
+ * returns 1 if there are entries in istate, 0 otherwise.  If an strbuf is
+ * provided, the space-separated list of files that differ will be appended
+ * to it.
  */
-extern int index_has_changes(struct strbuf *sb);
+extern int index_has_changes(const struct index_state *istate,
+                            struct tree *tree,
+                            struct strbuf *sb);
 
-extern int verify_path(const char *path);
+extern int verify_path(const char *path, unsigned mode);
 extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
 extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);
 extern void adjust_dirname_case(struct index_state *istate, char *name);
@@ -1161,7 +1169,15 @@ int normalize_path_copy(char *dst, const char *src);
 int longest_ancestor_length(const char *path, struct string_list *prefixes);
 char *strip_path_suffix(const char *path, const char *suffix);
 int daemon_avoid_alias(const char *path);
-extern int is_ntfs_dotgit(const char *name);
+
+/*
+ * These functions match their is_hfs_dotgit() counterparts; see utf8.h for
+ * details.
+ */
+int is_ntfs_dotgit(const char *name);
+int is_ntfs_dotgitmodules(const char *name);
+int is_ntfs_dotgitignore(const char *name);
+int is_ntfs_dotgitattributes(const char *name);
 
 /*
  * Returns true iff "str" could be confused as a command-line option when