1 files changed, 40 insertions, 18 deletions

diff --git a/diff.c b/diff.c
index 80eb0c2156..d3734d3181 100644
--- a/diff.c
+++ b/diff.c
@@ -26,6 +26,7 @@
 #endif
 
 static int diff_detect_rename_default;
+static int diff_compaction_heuristic = 1;
 static int diff_rename_limit_default = 400;
 static int diff_suppress_blank_empty;
 static int diff_use_color_default = -1;
@@ -168,6 +169,11 @@ long parse_algorithm_value(const char *value)
  * never be affected by the setting of diff.renames
  * the user happens to have in the configuration file.
  */
+void init_diff_ui_defaults(void)
+{
+	diff_detect_rename_default = 1;
+}
+
 int git_diff_ui_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
@@ -184,6 +190,10 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 		diff_detect_rename_default = git_config_rename(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "diff.compactionheuristic")) {
+		diff_compaction_heuristic = git_config_bool(var, value);
+		return 0;
+	}
 	if (!strcmp(var, "diff.autorefreshindex")) {
 		diff_auto_refresh_index = git_config_bool(var, value);
 		return 0;
@@ -2607,12 +2617,9 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 
 struct diff_filespec *alloc_filespec(const char *path)
 {
-	int namelen = strlen(path);
-	struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
+	struct diff_filespec *spec;
 
-	memset(spec, 0, sizeof(*spec));
-	spec->path = (char *)(spec + 1);
-	memcpy(spec->path, path, namelen+1);
+	FLEXPTR_ALLOC_STR(spec, path, path);
 	spec->count = 1;
 	spec->is_binary = -1;
 	return spec;
@@ -2707,21 +2714,21 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 
 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
 {
-	int len;
-	char *data = xmalloc(100), *dirty = "";
+	struct strbuf buf = STRBUF_INIT;
+	char *dirty = "";
 
 	/* Are we looking at the work tree? */
 	if (s->dirty_submodule)
 		dirty = "-dirty";
 
-	len = snprintf(data, 100,
-		       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
-	s->data = data;
-	s->size = len;
-	s->should_free = 1;
+	strbuf_addf(&buf, "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
+	s->size = buf.len;
 	if (size_only) {
 		s->data = NULL;
-		free(data);
+		strbuf_release(&buf);
+	} else {
+		s->data = strbuf_detach(&buf, NULL);
+		s->should_free = 1;
 	}
 	return 0;
 }
@@ -3276,6 +3283,8 @@ void diff_setup(struct diff_options *options)
 	options->use_color = diff_use_color_default;
 	options->detect_rename = diff_detect_rename_default;
 	options->xdl_opts |= diff_algorithm;
+	if (diff_compaction_heuristic)
+		DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
 
 	options->orderfile = diff_order_file_cfg;
 
@@ -3693,12 +3702,16 @@ static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
 	return 1;
 }
 
-int diff_opt_parse(struct diff_options *options, const char **av, int ac)
+int diff_opt_parse(struct diff_options *options,
+		   const char **av, int ac, const char *prefix)
 {
 	const char *arg = av[0];
 	const char *optarg;
 	int argcount;
 
+	if (!prefix)
+		prefix = "";
+
 	/* Output format options */
 	if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
 	    || opt_arg(arg, 'U', "unified", &options->context))
@@ -3792,6 +3805,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
 	else if (!strcmp(arg, "--ignore-blank-lines"))
 		DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
+	else if (!strcmp(arg, "--compaction-heuristic"))
+		DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
+	else if (!strcmp(arg, "--no-compaction-heuristic"))
+		DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
 	else if (!strcmp(arg, "--patience"))
 		options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
 	else if (!strcmp(arg, "--histogram"))
@@ -3915,7 +3932,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--pickaxe-regex"))
 		options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
 	else if ((argcount = short_opt('O', av, &optarg))) {
-		options->orderfile = optarg;
+		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+		options->orderfile = xstrdup(path);
 		return argcount;
 	}
 	else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
@@ -3954,9 +3972,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--no-function-context"))
 		DIFF_OPT_CLR(options, FUNCCONTEXT);
 	else if ((argcount = parse_long_opt("output", av, &optarg))) {
-		options->file = fopen(optarg, "w");
+		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+		options->file = fopen(path, "w");
 		if (!options->file)
-			die_errno("Could not open '%s'", optarg);
+			die_errno("Could not open '%s'", path);
 		options->close_file = 1;
 		return argcount;
 	} else
@@ -5079,7 +5098,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 {
 	size_t size;
 
-	if (!driver || !driver->textconv) {
+	if (!driver) {
 		if (!DIFF_FILE_VALID(df)) {
 			*outbuf = "";
 			return 0;
@@ -5090,6 +5109,9 @@ size_t fill_textconv(struct userdiff_driver *driver,
 		return df->size;
 	}
 
+	if (!driver->textconv)
+		die("BUG: fill_textconv called with non-textconv driver");
+
 	if (driver->textconv_cache && df->sha1_valid) {
 		*outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
 					  &size);