Merge branch 'cf/c23-const-preserving-strchr-updates-0'

ISO C23 redefines strchr and friends that tradiotionally took
a const pointer and returned a non-const pointer derived from it to
preserve constness (i.e., if you ask for a substring in a const
string, you get a const pointer to the substring).  Update code
paths that used non-const pointer to receive their results that did
not have to be non-const to adjust.

* cf/c23-const-preserving-strchr-updates-0:
  gpg-interface: remove an unnecessary NULL initialization
  global: constify some pointers that are not written to

add-patch.c

@@ -342,7 +342,7 @@ static int parse_hunk_header(struct add_p_state *s, struct hunk *hunk)
 {
 	struct hunk_header *header = &hunk->header;
 	const char *line = s->plain.buf + hunk->start, *p = line;
-	char *eol = memchr(p, '\n', s->plain.len - hunk->start);
+	const char *eol = memchr(p, '\n', s->plain.len - hunk->start);
 
 	if (!eol)
 		eol = s->plain.buf + s->plain.len;

apply.c

@@ -4144,7 +4144,7 @@ static int preimage_oid_in_gitlink_patch(struct patch *p, struct object_id *oid)
 	 */
 	struct fragment *hunk = p->fragments;
 	static const char heading[] = "-Subproject commit ";
-	char *preimage;
+	const char *preimage;
 
 	if (/* does the patch have only one hunk? */
 	    hunk && !hunk->next &&

builtin/commit.c

@@ -816,7 +816,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 				  logfile);
 		hook_arg1 = "message";
 	} else if (use_message) {
-		char *buffer;
+		const char *buffer;
 		buffer = strstr(use_message_buffer, "\n\n");
 		if (buffer)
 			strbuf_addstr(&sb, skip_blank_lines(buffer + 2));

builtin/receive-pack.c

@@ -393,7 +393,7 @@ struct command {
 static void proc_receive_ref_append(const char *prefix)
 {
 	struct proc_receive_ref *ref_pattern;
-	char *p;
+	const char *p;
 	int len;
 
 	CALLOC_ARRAY(ref_pattern, 1);

builtin/remote.c

@@ -332,7 +332,7 @@ static int config_read_branches(const char *key, const char *value,
 		info->remote_name = xstrdup(value);
 		break;
 	case MERGE: {
-		char *space = strchr(value, ' ');
+		const char *space = strchr(value, ' ');
 		value = abbrev_branch(value);
 		while (space) {
 			char *merge;

builtin/shortlog.c

@@ -76,7 +76,7 @@ static void insert_one_record(struct shortlog *log,
 		if (!eol)
 			eol = oneline + strlen(oneline);
 		if (starts_with(oneline, "[PATCH")) {
-			char *eob = strchr(oneline, ']');
+			const char *eob = strchr(oneline, ']');
 			if (eob && (!eol || eob < eol))
 				oneline = eob + 1;
 		}

config.c

@@ -160,7 +160,7 @@ static int handle_path_include(const struct key_value_info *kvi,
 	 * based on the including config file.
 	 */
 	if (!is_absolute_path(path)) {
-		char *slash;
+		const char *slash;
 
 		if (!kvi || kvi->origin_type != CONFIG_ORIGIN_FILE) {
 			ret = error(_("relative config includes must come from files"));

convert.c

@@ -1122,7 +1122,8 @@ static int count_ident(const char *cp, unsigned long size)
 static int ident_to_git(const char *src, size_t len,
 			struct strbuf *buf, int ident)
 {
-	char *dst, *dollar;
+	char *dst;
+	const char *dollar;
 
 	if (!ident || (src && !count_ident(src, len)))
 		return 0;

diff.c

@@ -1961,7 +1961,7 @@ static int fn_out_diff_words_write_helper(struct diff_options *o,
 	struct strbuf sb = STRBUF_INIT;
 
 	while (count) {
-		char *p = memchr(buf, '\n', count);
+		const char *p = memchr(buf, '\n', count);
 		if (print)
 			strbuf_addstr(&sb, diff_line_prefix(o));
 
@@ -3044,7 +3044,7 @@ static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
 		struct dirstat_file *f = dir->files;
 		int namelen = strlen(f->name);
 		unsigned long changes;
-		char *slash;
+		const char *slash;
 
 		if (namelen < baselen)
 			break;

diffcore-rename.c

@@ -379,7 +379,7 @@ struct dir_rename_info {
 
 static char *get_dirname(const char *filename)
 {
-	char *slash = strrchr(filename, '/');
+	const char *slash = strrchr(filename, '/');
 	return slash ? xstrndup(filename, slash - filename) : xstrdup("");
 }
 

fmt-merge-msg.c

@@ -246,7 +246,8 @@ static void add_branch_desc(struct strbuf *out, const char *name)
 static void record_person_from_buf(int which, struct string_list *people,
 				   const char *buffer)
 {
-	char *name_buf, *name, *name_end;
+	char *name_buf;
+	const char *name, *name_end;
 	struct string_list_item *elem;
 	const char *field;
 

fsck.c

@@ -1026,7 +1026,7 @@ int fsck_tag_standalone(const struct object_id *oid, const char *buffer,
 			int *tagged_type)
 {
 	int ret = 0;
-	char *eol;
+	const char *eol;
 	struct strbuf sb = STRBUF_INIT;
 	const char *buffer_end = buffer + size;
 	const char *p;

gpg-interface.c

@@ -398,7 +398,7 @@ static void parse_ssh_output(struct signature_check *sigc)
 {
 	const char *line, *principal, *search;
 	char *to_free;
-	char *key = NULL;
+	const char *key;
 
 	/*
 	 * ssh-keygen output should be:

help.c

@@ -856,7 +856,7 @@ struct similar_ref_cb {
 static int append_similar_ref(const struct reference *ref, void *cb_data)
 {
 	struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
-	char *branch = strrchr(ref->name, '/') + 1;
+	const char *branch = strrchr(ref->name, '/') + 1;
 
 	/* A remote branch of the same name is deemed similar */
 	if (starts_with(ref->name, "refs/remotes/") &&

http-push.c

@@ -1768,7 +1768,7 @@ int cmd_main(int argc, const char **argv)
 				usage(http_push_usage);
 		}
 		if (!repo->url) {
-			char *path = strstr(arg, "//");
+			const char *path = strstr(arg, "//");
 			str_end_url_with_slash(arg, &repo->url);
 			repo->path_len = strlen(repo->url);
 			if (path) {

mailinfo.c

@@ -1141,7 +1141,7 @@ static void output_header_lines(FILE *fout, const char *hdr, const struct strbuf
 {
 	const char *sp = data->buf;
 	while (1) {
-		char *ep = strchr(sp, '\n');
+		const char *ep = strchr(sp, '\n');
 		int len;
 		if (!ep)
 			len = strlen(sp);

mem-pool.c

@@ -169,7 +169,7 @@ char *mem_pool_strdup(struct mem_pool *pool, const char *str)
 
 char *mem_pool_strndup(struct mem_pool *pool, const char *str, size_t len)
 {
-	char *p = memchr(str, '\0', len);
+	const char *p = memchr(str, '\0', len);
 	size_t actual_len = (p ? p - str : len);
 	char *ret = mem_pool_alloc(pool, actual_len+1);
 

merge-ort.c

@@ -2731,7 +2731,7 @@ static void apply_directory_rename_modifications(struct merge_options *opt,
 
 	while (1) {
 		/* Find the parent directory of cur_path */
-		char *last_slash = strrchr(cur_path, '/');
+		const char *last_slash = strrchr(cur_path, '/');
 		if (last_slash) {
 			parent_name = mem_pool_strndup(&opt->priv->pool,
 						       cur_path,

object-name.c

@@ -1756,7 +1756,7 @@ int repo_interpret_branch_name(struct repository *r,
 			       struct strbuf *buf,
 			       const struct interpret_branch_name_options *options)
 {
-	char *at;
+	const char *at;
 	const char *start;
 	int len;
 

pack-revindex.c

@@ -544,7 +544,7 @@ static int midx_key_to_pack_pos(struct multi_pack_index *m,
 				struct midx_pack_key *key,
 				uint32_t *pos)
 {
-	uint32_t *found;
+	const uint32_t *found;
 
 	if (key->pack >= m->num_packs + m->num_packs_in_base)
 		BUG("MIDX pack lookup out of bounds (%"PRIu32" >= %"PRIu32")",

pkt-line.c

@@ -384,10 +384,10 @@ int packet_length(const char lenbuf_hex[4], size_t size)
 		hexval(lenbuf_hex[3]);
 }
 
-static char *find_packfile_uri_path(const char *buffer)
+static const char *find_packfile_uri_path(const char *buffer)
 {
 	const char *URI_MARK = "://";
-	char *path;
+	const char *path;
 	int len;
 
 	/* First char is sideband mark */
@@ -417,7 +417,7 @@ enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 {
 	int len;
 	char linelen[4];
-	char *uri_path_start;
+	const char *uri_path_start;
 
 	if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
 		*pktlen = -1;

reflog-walk.c

@@ -157,7 +157,8 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
 	int recno = -1;
 	struct string_list_item *item;
 	struct complete_reflogs *reflogs;
-	char *branch, *at = strchr(name, '@');
+	char *branch;
+	const char *at = strchr(name, '@');
 	struct commit_reflog *commit_reflog;
 	enum selector_type selector = SELECTOR_NONE;
 

scalar.c

@@ -393,7 +393,7 @@ static int delete_enlistment(struct strbuf *enlistment)
 {
 	struct strbuf parent = STRBUF_INIT;
 	size_t offset;
-	char *path_sep;
+	const char *path_sep;
 
 	if (unregister_dir())
 		return error(_("failed to unregister repository"));

strbuf.c

@@ -1119,6 +1119,6 @@ void strbuf_stripspace(struct strbuf *sb, const char *comment_prefix)
 
 void strbuf_strip_file_from_path(struct strbuf *sb)
 {
-	char *path_sep = find_last_dir_sep(sb->buf);
+	const char *path_sep = find_last_dir_sep(sb->buf);
 	strbuf_setlen(sb, path_sep ? path_sep - sb->buf + 1 : 0);
 }

string-list.c

@@ -333,7 +333,7 @@ static int split_string(struct string_list *list, const char *string, const char
 		BUG("string_list_split() called without strdup_strings");
 
 	for (;;) {
-		char *end;
+		const char *end;
 
 		if (flags & STRING_LIST_SPLIT_TRIM) {
 			/* ltrim */

t/unit-tests/clar/clar/print.h

@@ -127,7 +127,7 @@ static void clar_print_tap_error(int num, const struct clar_report *report, cons
 
 static void print_escaped(const char *str)
 {
-	char *c;
+	const char *c;
 
 	while ((c = strchr(str, '\'')) != NULL) {
 		printf("%.*s", (int)(c - str), str);

transport.c

@@ -1657,7 +1657,7 @@ int transport_disconnect(struct transport *transport)
  */
 char *transport_anonymize_url(const char *url)
 {
-	char *scheme_prefix, *anon_part;
+	const char *scheme_prefix, *anon_part;
 	size_t anon_len, prefix_len = 0;
 
 	anon_part = strchr(url, '@');

wrapper.c

@@ -115,7 +115,7 @@ void *xmemdupz(const void *data, size_t len)
 
 char *xstrndup(const char *str, size_t len)
 {
-	char *p = memchr(str, '\0', len);
+	const char *p = memchr(str, '\0', len);
 	return xmemdupz(str, p ? p - str : len);
 }