prefix_filename: drop length parameter

This function takes the prefix as a ptr/len pair, but in
every caller the length is exactly strlen(ptr). Let's
simplify the interface and just take the string. This saves
callers specifying it (and in some cases handling a NULL
prefix).

In a handful of cases we had the length already without
calling strlen, so this is technically slower. But it's not
likely to matter (after all, if the prefix is non-empty
we'll allocate and copy it into a buffer anyway).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

abspath.c

@@ -246,9 +246,11 @@ char *absolute_pathdup(const char *path)
 	return strbuf_detach(&sb, NULL);
 }
 
-const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
+const char *prefix_filename(const char *pfx, const char *arg)
 {
 	static struct strbuf path = STRBUF_INIT;
+	size_t pfx_len = pfx ? strlen(pfx) : 0;
+
 #ifndef GIT_WINDOWS_NATIVE
 	if (!pfx_len || is_absolute_path(arg))
 		return arg;

apply.c

@@ -2046,7 +2046,7 @@ static void prefix_one(struct apply_state *state, char **name)
 	char *old_name = *name;
 	if (!old_name)
 		return;
-	*name = xstrdup(prefix_filename(state->prefix, state->prefix_length, *name));
+	*name = xstrdup(prefix_filename(state->prefix, *name));
 	free(old_name);
 }
 
@@ -4815,9 +4815,7 @@ int apply_all_patches(struct apply_state *state,
 			read_stdin = 0;
 			continue;
 		} else if (0 < state->prefix_length)
-			arg = prefix_filename(state->prefix,
-					      state->prefix_length,
-					      arg);
+			arg = prefix_filename(state->prefix, arg);
 
 		fd = open(arg, O_RDONLY);
 		if (fd < 0) {

builtin/config.c

@@ -528,7 +528,6 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		if (!is_absolute_path(given_config_source.file) && prefix)
 			given_config_source.file =
 				xstrdup(prefix_filename(prefix,
-							strlen(prefix),
 							given_config_source.file));
 	}
 

builtin/hash-object.c

@@ -102,7 +102,6 @@ int cmd_hash_object(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 	int i;
-	int prefix_length = -1;
 	const char *errstr = NULL;
 
 	argc = parse_options(argc, argv, NULL, hash_object_options,
@@ -113,9 +112,8 @@ int cmd_hash_object(int argc, const char **argv, const char *prefix)
 	else
 		prefix = setup_git_directory_gently(&nongit);
 
-	prefix_length = prefix ? strlen(prefix) : 0;
 	if (vpath && prefix)
-		vpath = xstrdup(prefix_filename(prefix, prefix_length, vpath));
+		vpath = xstrdup(prefix_filename(prefix, vpath));
 
 	git_config(git_default_config, NULL);
 
@@ -146,9 +144,8 @@ int cmd_hash_object(int argc, const char **argv, const char *prefix)
 		const char *arg = argv[i];
 		char *to_free = NULL;
 
-		if (0 <= prefix_length)
-			arg = to_free =
-				xstrdup(prefix_filename(prefix, prefix_length, arg));
+		if (prefix)
+			arg = to_free = xstrdup(prefix_filename(prefix, arg));
 		hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
 			    flags, literally);
 		free(to_free);

builtin/log.c

@@ -1084,8 +1084,7 @@ static const char *set_outdir(const char *prefix, const char *output_directory)
 	if (!output_directory)
 		return prefix;
 
-	return xstrdup(prefix_filename(prefix, outdir_offset,
-				       output_directory));
+	return xstrdup(prefix_filename(prefix, output_directory));
 }
 
 static const char * const builtin_format_patch_usage[] = {

builtin/mailinfo.c

@@ -15,7 +15,7 @@ static char *prefix_copy(const char *prefix, const char *filename)
 {
 	if (!prefix || is_absolute_path(filename))
 		return xstrdup(filename);
-	return xstrdup(prefix_filename(prefix, strlen(prefix), filename));
+	return xstrdup(prefix_filename(prefix, filename));
 }
 
 int cmd_mailinfo(int argc, const char **argv, const char *prefix)

builtin/merge-file.c

@@ -28,7 +28,6 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
 	xmparam_t xmp = {{0}};
 	int ret = 0, i = 0, to_stdout = 0;
 	int quiet = 0;
-	int prefixlen = 0;
 	struct option options[] = {
 		OPT_BOOL('p', "stdout", &to_stdout, N_("send results to standard output")),
 		OPT_SET_INT(0, "diff3", &xmp.style, N_("use a diff3 based merge"), XDL_MERGE_DIFF3),
@@ -65,11 +64,8 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
 			return error_errno("failed to redirect stderr to /dev/null");
 	}
 
-	if (prefix)
-		prefixlen = strlen(prefix);
-
 	for (i = 0; i < 3; i++) {
-		const char *fname = prefix_filename(prefix, prefixlen, argv[i]);
+		const char *fname = prefix_filename(prefix, argv[i]);
 		if (!names[i])
 			names[i] = argv[i];
 		if (read_mmfile(mmfs + i, fname))
@@ -90,7 +86,7 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
 
 	if (ret >= 0) {
 		const char *filename = argv[0];
-		const char *fpath = prefix_filename(prefix, prefixlen, argv[0]);
+		const char *fpath = prefix_filename(prefix, argv[0]);
 		FILE *f = to_stdout ? stdout : fopen(fpath, "wb");
 
 		if (!f)

builtin/rev-parse.c

@@ -228,9 +228,7 @@ static int show_file(const char *arg, int output_prefix)
 	if ((filter & (DO_NONFLAGS|DO_NOREV)) == (DO_NONFLAGS|DO_NOREV)) {
 		if (output_prefix) {
 			const char *prefix = startup_info->prefix;
-			show(prefix_filename(prefix,
-					     prefix ? strlen(prefix) : 0,
-					     arg));
+			show(prefix_filename(prefix, arg));
 		} else
 			show(arg);
 		return 1;

builtin/worktree.c

@@ -338,7 +338,7 @@ static int add(int ac, const char **av, const char *prefix)
 	if (ac < 1 || ac > 2)
 		usage_with_options(worktree_usage, options);
 
-	path = prefix_filename(prefix, strlen(prefix), av[0]);
+	path = prefix_filename(prefix, av[0]);
 	branch = ac < 2 ? "HEAD" : av[1];
 
 	if (!strcmp(branch, "-"))

cache.h

@@ -540,7 +540,7 @@ extern char *prefix_path_gently(const char *prefix, int len, int *remaining, con
  * The return value may point to static storage which will be overwritten by
  * further calls.
  */
-extern const char *prefix_filename(const char *prefix, int len, const char *path);
+extern const char *prefix_filename(const char *prefix, const char *path);
 
 extern int check_filename(const char *prefix, const char *name);
 extern void verify_filename(const char *prefix,

diff-no-index.c

@@ -236,7 +236,7 @@ static void fixup_paths(const char **path, struct strbuf *replacement)
 void diff_no_index(struct rev_info *revs,
 		   int argc, const char **argv)
 {
-	int i, prefixlen;
+	int i;
 	const char *paths[2];
 	struct strbuf replacement = STRBUF_INIT;
 	const char *prefix = revs->prefix;
@@ -257,7 +257,6 @@ void diff_no_index(struct rev_info *revs,
 		}
 	}
 
-	prefixlen = prefix ? strlen(prefix) : 0;
 	for (i = 0; i < 2; i++) {
 		const char *p = argv[argc - 2 + i];
 		if (!strcmp(p, "-"))
@@ -266,8 +265,8 @@ void diff_no_index(struct rev_info *revs,
 			 * path that is "-", spell it as "./-".
 			 */
 			p = file_from_standard_input;
-		else if (prefixlen)
-			p = xstrdup(prefix_filename(prefix, prefixlen, p));
+		else if (prefix)
+			p = xstrdup(prefix_filename(prefix, p));
 		paths[i] = p;
 	}
 

diff.c

@@ -4023,7 +4023,7 @@ int diff_opt_parse(struct diff_options *options,
 	else if (!strcmp(arg, "--pickaxe-regex"))
 		options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
 	else if ((argcount = short_opt('O', av, &optarg))) {
-		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+		const char *path = prefix_filename(prefix, optarg);
 		options->orderfile = xstrdup(path);
 		return argcount;
 	}
@@ -4071,7 +4071,7 @@ int diff_opt_parse(struct diff_options *options,
 	else if (!strcmp(arg, "--no-function-context"))
 		DIFF_OPT_CLR(options, FUNCCONTEXT);
 	else if ((argcount = parse_long_opt("output", av, &optarg))) {
-		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+		const char *path = prefix_filename(prefix, optarg);
 		options->file = fopen(path, "w");
 		if (!options->file)
 			die_errno("Could not open '%s'", path);

parse-options.c

@@ -40,7 +40,7 @@ static void fix_filename(const char *prefix, const char **file)
 	if (!file || !*file || !prefix || is_absolute_path(*file)
 	    || !strcmp("-", *file))
 		return;
-	*file = xstrdup(prefix_filename(prefix, strlen(prefix), *file));
+	*file = xstrdup(prefix_filename(prefix, *file));
 }
 
 static int opt_command_mode_error(const struct option *opt,

setup.c

@@ -142,7 +142,7 @@ int check_filename(const char *prefix, const char *arg)
 			return 1;
 		name = arg + 2;
 	} else if (prefix)
-		name = prefix_filename(prefix, strlen(prefix), arg);
+		name = prefix_filename(prefix, arg);
 	else
 		name = arg;
 	if (!lstat(name, &st))

worktree.c

@@ -254,7 +254,7 @@ struct worktree *find_worktree(struct worktree **list,
 	if ((wt = find_worktree_by_suffix(list, arg)))
 		return wt;
 
-	arg = prefix_filename(prefix, strlen(prefix), arg);
+	arg = prefix_filename(prefix, arg);
 	path = real_pathdup(arg, 1);
 	for (; *list; list++)
 		if (!fspathcmp(path, real_path((*list)->path)))