Merge branch 'jc/string-list-split' into seen

gitster · gitster · commit c80a40a27ce9 · 2025-08-01T12:26:36.000-07:00
string_list_split*() family of functions have been extended to
simplify common use cases.

Comments?

* jc/string-list-split:
  string-list: split-then-remove-empty can be done while splitting
  string-list: optionally omit empty string pieces in string_list_split*()
  diff: simplify parsing of diff.colormovedws
  string-list: optionally trim string pieces split by string_list_split*()
  string-list: unify string_list_split* functions
  string-list: align string_list_split() with its _in_place() counterpart
  string-list: report programming error with BUG
diff --git a/builtin/blame.c b/builtin/blame.c
@@ -413,7 +413,7 @@ static void parse_color_fields(const char *s)
 	colorfield_nr = 0;
 
 	/* Ideally this would be stripped and split at the same time? */
-	string_list_split(&l, s, ',', -1);
+	string_list_split(&l, s, ",", -1);
 	ALLOC_GROW(colorfield, colorfield_nr + 1, colorfield_alloc);
 
 	for_each_string_list_item(item, &l) {
diff --git a/builtin/merge.c b/builtin/merge.c
@@ -875,7 +875,7 @@ static void add_strategies(const char *string, unsigned attr)
 	if (string) {
 		struct string_list list = STRING_LIST_INIT_DUP;
 		struct string_list_item *item;
-		string_list_split(&list, string, ' ', -1);
+		string_list_split(&list, string, " ", -1);
 		for_each_string_list_item(item, &list)
 			append_strategy(get_strategy(item->string));
 		string_list_clear(&list, 0);
diff --git a/builtin/var.c b/builtin/var.c
@@ -182,7 +182,7 @@ static void list_vars(void)
 			if (ptr->multivalued && *val) {
 				struct string_list list = STRING_LIST_INIT_DUP;
 
-				string_list_split(&list, val, '\n', -1);
+				string_list_split(&list, val, "\n", -1);
 				for (size_t i = 0; i < list.nr; i++)
 					printf("%s=%s\n", ptr->name, list.items[i].string);
 				string_list_clear(&list, 0);
diff --git a/connect.c b/connect.c
@@ -407,7 +407,7 @@ static int process_ref_v2(struct packet_reader *reader, struct ref ***list,
 	 * name.  Subsequent fields (symref-target and peeled) are optional and
 	 * don't have a particular order.
 	 */
-	if (string_list_split(&line_sections, line, ' ', -1) < 2) {
+	if (string_list_split(&line_sections, line, " ", -1) < 2) {
 		ret = 0;
 		goto out;
 	}
diff --git a/diff.c b/diff.c
@@ -327,29 +327,23 @@ static unsigned parse_color_moved_ws(const char *arg)
 	struct string_list l = STRING_LIST_INIT_DUP;
 	struct string_list_item *i;
 
-	string_list_split(&l, arg, ',', -1);
+	string_list_split_f(&l, arg, ",", -1, STRING_LIST_SPLIT_TRIM);
 
 	for_each_string_list_item(i, &l) {
-		struct strbuf sb = STRBUF_INIT;
-		strbuf_addstr(&sb, i->string);
-		strbuf_trim(&sb);
-
-		if (!strcmp(sb.buf, "no"))
+		if (!strcmp(i->string, "no"))
 			ret = 0;
-		else if (!strcmp(sb.buf, "ignore-space-change"))
+		else if (!strcmp(i->string, "ignore-space-change"))
 			ret |= XDF_IGNORE_WHITESPACE_CHANGE;
-		else if (!strcmp(sb.buf, "ignore-space-at-eol"))
+		else if (!strcmp(i->string, "ignore-space-at-eol"))
 			ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
-		else if (!strcmp(sb.buf, "ignore-all-space"))
+		else if (!strcmp(i->string, "ignore-all-space"))
 			ret |= XDF_IGNORE_WHITESPACE;
-		else if (!strcmp(sb.buf, "allow-indentation-change"))
+		else if (!strcmp(i->string, "allow-indentation-change"))
 			ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 		else {
 			ret |= COLOR_MOVED_WS_ERROR;
-			error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
+			error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), i->string);
 		}
-
-		strbuf_release(&sb);
 	}
 
 	if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
diff --git a/fetch-pack.c b/fetch-pack.c
@@ -1914,7 +1914,7 @@ static void fetch_pack_config(void)
 		char *str;
 
 		if (!repo_config_get_string(the_repository, "fetch.uriprotocols", &str) && str) {
-			string_list_split(&uri_protocols, str, ',', -1);
+			string_list_split(&uri_protocols, str, ",", -1);
 			free(str);
 		}
 	}
diff --git a/notes.c b/notes.c
@@ -894,7 +894,7 @@ static int string_list_add_note_lines(struct string_list *list,
 	 * later, along with any empty strings that came from empty
 	 * lines within the file.
 	 */
-	string_list_split(list, data, '\n', -1);
+	string_list_split(list, data, "\n", -1);
 	free(data);
 	return 0;
 }
@@ -973,8 +973,8 @@ void string_list_add_refs_from_colon_sep(struct string_list *list,
 	char *globs_copy = xstrdup(globs);
 	int i;
 
-	string_list_split_in_place(&split, globs_copy, ":", -1);
-	string_list_remove_empty_items(&split, 0);
+	string_list_split_in_place_f(&split, globs_copy, ":", -1,
+				     STRING_LIST_SPLIT_NONEMPTY);
 
 	for (i = 0; i < split.nr; i++)
 		string_list_add_refs_by_glob(list, split.items[i].string);
diff --git a/parse-options.c b/parse-options.c
@@ -1338,7 +1338,7 @@ static enum parse_opt_result usage_with_options_internal(struct parse_opt_ctx_t
 		if (!saw_empty_line && !*str)
 			saw_empty_line = 1;
 
-		string_list_split(&list, str, '\n', -1);
+		string_list_split(&list, str, "\n", -1);
 		for (j = 0; j < list.nr; j++) {
 			const char *line = list.items[j].string;
 
diff --git a/pathspec.c b/pathspec.c
@@ -201,8 +201,7 @@ static void parse_pathspec_attr_match(struct pathspec_item *item, const char *va
 	if (!value || !*value)
 		die(_("attr spec must not be empty"));
 
-	string_list_split(&list, value, ' ', -1);
-	string_list_remove_empty_items(&list, 0);
+	string_list_split_f(&list, value, " ", -1, STRING_LIST_SPLIT_NONEMPTY);
 
 	item->attr_check = attr_check_alloc();
 	CALLOC_ARRAY(item->attr_match, list.nr);
diff --git a/protocol.c b/protocol.c
@@ -61,7 +61,7 @@ enum protocol_version determine_protocol_version_server(void)
 	if (git_protocol) {
 		struct string_list list = STRING_LIST_INIT_DUP;
 		const struct string_list_item *item;
-		string_list_split(&list, git_protocol, ':', -1);
+		string_list_split(&list, git_protocol, ":", -1);
 
 		for_each_string_list_item(item, &list) {
 			const char *value;
diff --git a/ref-filter.c b/ref-filter.c
@@ -435,7 +435,7 @@ static int remote_ref_atom_parser(struct ref_format *format UNUSED,
 	}
 
 	atom->u.remote_ref.nobracket = 0;
-	string_list_split(&params, arg, ',', -1);
+	string_list_split(&params, arg, ",", -1);
 
 	for (i = 0; i < params.nr; i++) {
 		const char *s = params.items[i].string;
@@ -831,7 +831,7 @@ static int align_atom_parser(struct ref_format *format UNUSED,
 
 	align->position = ALIGN_LEFT;
 
-	string_list_split(&params, arg, ',', -1);
+	string_list_split(&params, arg, ",", -1);
 	for (i = 0; i < params.nr; i++) {
 		const char *s = params.items[i].string;
 		int position;
diff --git a/setup.c b/setup.c
@@ -1460,8 +1460,9 @@ static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
 
 	if (env_ceiling_dirs) {
 		int empty_entry_found = 0;
+		static const char path_sep[] = { PATH_SEP, '\0' };
 
-		string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
+		string_list_split(&ceiling_dirs, env_ceiling_dirs, path_sep, -1);
 		filter_string_list(&ceiling_dirs, 0,
 				   canonicalize_ceiling_entry, &empty_entry_found);
 		ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
diff --git a/string-list.c b/string-list.c
@@ -276,55 +276,99 @@ void unsorted_string_list_delete_item(struct string_list *list, int i, int free_
 	list->nr--;
 }
 
-int string_list_split(struct string_list *list, const char *string,
-		      int delim, int maxsplit)
+/*
+ * append a substring [p..end] to list; return number of things it
+ * appended to the list.
+ */
+static int append_one(struct string_list *list,
+		      const char *p, const char *end,
+		      int in_place, unsigned flags)
+{
+	if (!end)
+		end = p + strlen(p);
+
+	if ((flags & STRING_LIST_SPLIT_TRIM)) {
+		/* rtrim */
+		for (; p < end; end--)
+			if (!isspace(end[-1]))
+				break;
+	}
+
+	if ((flags & STRING_LIST_SPLIT_NONEMPTY) && (end <= p))
+		return 0;
+
+	if (in_place) {
+		*((char *)end) = '\0';
+		string_list_append(list, p);
+	} else {
+		string_list_append_nodup(list, xmemdupz(p, end - p));
+	}
+	return 1;
+}
+
+/*
+ * Unfortunately this cannot become a public interface, as _in_place()
+ * wants to have "const char *string" while the other variant wants to
+ * have "char *string" for type safety.
+ *
+ * This accepts "const char *string" to allow both wrappers to use it;
+ * it internally casts away the constness when in_place is true by
+ * taking advantage of strpbrk() that takes a "const char *" arg and
+ * returns "char *" pointer into that const string.  Yucky but works ;-).
+ */
+static int split_string(struct string_list *list, const char *string, const char *delim,
+			int maxsplit, int in_place, unsigned flags)
 {
 	int count = 0;
-	const char *p = string, *end;
+	const char *p = string;
+
+	if (in_place && list->strdup_strings)
+		BUG("string_list_split_in_place() called with strdup_strings");
+	else if (!in_place && !list->strdup_strings)
+		BUG("string_list_split() called without strdup_strings");
 
-	if (!list->strdup_strings)
-		die("internal error in string_list_split(): "
-		    "list->strdup_strings must be set");
 	for (;;) {
-		count++;
-		if (maxsplit >= 0 && count > maxsplit) {
-			string_list_append(list, p);
-			return count;
+		char *end;
+
+		if (flags & STRING_LIST_SPLIT_TRIM) {
+			/* ltrim */
+			while (*p && isspace(*p))
+				p++;
 		}
-		end = strchr(p, delim);
-		if (end) {
-			string_list_append_nodup(list, xmemdupz(p, end - p));
-			p = end + 1;
-		} else {
-			string_list_append(list, p);
+
+		if (0 <= maxsplit && maxsplit <= count)
+			end = NULL;
+		else
+			end = strpbrk(p, delim);
+
+		count += append_one(list, p, end, in_place, flags);
+
+		if (!end)
 			return count;
-		}
+		p = end + 1;
 	}
 }
 
+int string_list_split(struct string_list *list, const char *string,
+		      const char *delim, int maxsplit)
+{
+	return split_string(list, string, delim, maxsplit, 0, 0);
+}
+
 int string_list_split_in_place(struct string_list *list, char *string,
 			       const char *delim, int maxsplit)
 {
-	int count = 0;
-	char *p = string, *end;
+	return split_string(list, string, delim, maxsplit, 1, 0);
+}
 
-	if (list->strdup_strings)
-		die("internal error in string_list_split_in_place(): "
-		    "list->strdup_strings must not be set");
-	for (;;) {
-		count++;
-		if (maxsplit >= 0 && count > maxsplit) {
-			string_list_append(list, p);
-			return count;
-		}
-		end = strpbrk(p, delim);
-		if (end) {
-			*end = '\0';
-			string_list_append(list, p);
-			p = end + 1;
-		} else {
-			string_list_append(list, p);
-			return count;
-		}
-	}
+int string_list_split_f(struct string_list *list, const char *string,
+			const char *delim, int maxsplit, unsigned flags)
+{
+	return split_string(list, string, delim, maxsplit, 0, flags);
+}
+
+int string_list_split_in_place_f(struct string_list *list, char *string,
+			       const char *delim, int maxsplit, unsigned flags)
+{
+	return split_string(list, string, delim, maxsplit, 1, flags);
 }
diff --git a/string-list.h b/string-list.h
@@ -254,23 +254,23 @@ struct string_list_item *unsorted_string_list_lookup(struct string_list *list,
 void unsorted_string_list_delete_item(struct string_list *list, int i, int free_util);
 
 /**
- * Split string into substrings on character `delim` and append the
+ * Split string into substrings on characters in `delim` and append the
  * substrings to `list`.  The input string is not modified.
  * list->strdup_strings must be set, as new memory needs to be
  * allocated to hold the substrings.  If maxsplit is non-negative,
  * then split at most maxsplit times.  Return the number of substrings
  * appended to list.
  *
  * Examples:
- *   string_list_split(l, "foo:bar:baz", ':', -1) -> ["foo", "bar", "baz"]
- *   string_list_split(l, "foo:bar:baz", ':', 0) -> ["foo:bar:baz"]
- *   string_list_split(l, "foo:bar:baz", ':', 1) -> ["foo", "bar:baz"]
- *   string_list_split(l, "foo:bar:", ':', -1) -> ["foo", "bar", ""]
- *   string_list_split(l, "", ':', -1) -> [""]
- *   string_list_split(l, ":", ':', -1) -> ["", ""]
+ *   string_list_split(l, "foo:bar:baz", ":", -1) -> ["foo", "bar", "baz"]
+ *   string_list_split(l, "foo:bar:baz", ":", 0) -> ["foo:bar:baz"]
+ *   string_list_split(l, "foo:bar:baz", ":", 1) -> ["foo", "bar:baz"]
+ *   string_list_split(l, "foo:bar:", ":", -1) -> ["foo", "bar", ""]
+ *   string_list_split(l, "", ":", -1) -> [""]
+ *   string_list_split(l, ":", ":", -1) -> ["", ""]
  */
 int string_list_split(struct string_list *list, const char *string,
-		      int delim, int maxsplit);
+		      const char *delim, int maxsplit);
 
 /*
  * Like string_list_split(), except that string is split in-place: the
@@ -281,4 +281,18 @@ int string_list_split(struct string_list *list, const char *string,
  */
 int string_list_split_in_place(struct string_list *list, char *string,
 			       const char *delim, int maxsplit);
+
+/* flag bits for split_f and split_in_place_f functions */
+enum {
+	/* trim() resulting string piece before adding it to the list */
+	STRING_LIST_SPLIT_TRIM = (1 << 0),
+	/* omit adding empty string piece to the resulting list */
+	STRING_LIST_SPLIT_NONEMPTY = (1 << 1),
+};
+
+int string_list_split_f(struct string_list *, const char *string,
+			const char *delim, int maxsplit, unsigned flags);
+
+int string_list_split_in_place_f(struct string_list *, char *string,
+				 const char *delim, int maxsplit, unsigned flags);
 #endif /* STRING_LIST_H */
diff --git a/t/helper/test-hashmap.c b/t/helper/test-hashmap.c
@@ -154,8 +154,8 @@ int cmd__hashmap(int argc UNUSED, const char **argv UNUSED)
 
 		/* break line into command and up to two parameters */
 		string_list_setlen(&parts, 0);
-		string_list_split_in_place(&parts, line.buf, DELIM, 2);
-		string_list_remove_empty_items(&parts, 0);
+		string_list_split_in_place_f(&parts, line.buf, DELIM, 2,
+					     STRING_LIST_SPLIT_NONEMPTY);
 
 		/* ignore empty lines */
 		if (!parts.nr)
diff --git a/t/helper/test-json-writer.c b/t/helper/test-json-writer.c
@@ -492,8 +492,8 @@ static int scripted(void)
 
 		/* break line into command and zero or more tokens */
 		string_list_setlen(&parts, 0);
-		string_list_split_in_place(&parts, line, " ", -1);
-		string_list_remove_empty_items(&parts, 0);
+		string_list_split_in_place_f(&parts, line, " ", -1,
+					     STRING_LIST_SPLIT_NONEMPTY);
 
 		/* ignore empty lines */
 		if (!parts.nr || !*parts.items[0].string)
diff --git a/t/helper/test-path-utils.c b/t/helper/test-path-utils.c
@@ -348,6 +348,7 @@ int cmd__path_utils(int argc, const char **argv)
 	if (argc == 4 && !strcmp(argv[1], "longest_ancestor_length")) {
 		int len;
 		struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
+		const char path_sep[] = { PATH_SEP, '\0' };
 		char *path = xstrdup(argv[2]);
 
 		/*
@@ -362,7 +363,7 @@ int cmd__path_utils(int argc, const char **argv)
 		 */
 		if (normalize_path_copy(path, path))
 			die("Path \"%s\" could not be normalized", argv[2]);
-		string_list_split(&ceiling_dirs, argv[3], PATH_SEP, -1);
+		string_list_split(&ceiling_dirs, argv[3], path_sep, -1);
 		filter_string_list(&ceiling_dirs, 0,
 				   normalize_ceiling_entry, NULL);
 		len = longest_ancestor_length(path, &ceiling_dirs);
diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
@@ -29,7 +29,7 @@ static unsigned int parse_flags(const char *str, struct flag_definition *defs)
 	if (!strcmp(str, "0"))
 		return 0;
 
-	string_list_split(&masks, str, ',', 64);
+	string_list_split(&masks, str, ",", 64);
 	for (size_t i = 0; i < masks.nr; i++) {
 		const char *name = masks.items[i].string;
 		struct flag_definition *def = defs;
diff --git a/t/unit-tests/u-string-list.c b/t/unit-tests/u-string-list.c
diff --git a/transport.c b/transport.c
diff --git a/upload-pack.c b/upload-pack.c

Original file line number	Diff line number	Diff line change
`@@ -407,7 +407,7 @@ static int process_ref_v2(struct packet_reader reader, struct ref **list,`
`407`	`407`	`* name. Subsequent fields (symref-target and peeled) are optional and`
`408`	`408`	`* don't have a particular order.`
`409`	`409`	`*/`
`410`		`- if (string_list_split(&line_sections, line, ' ', -1) < 2) {`
	`410`	`+ if (string_list_split(&line_sections, line, " ", -1) < 2) {`
`411`	`411`	`ret = 0;`
`412`	`412`	`goto out;`
`413`	`413`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1914,7 +1914,7 @@ static void fetch_pack_config(void)`
`1914`	`1914`	`char *str;`
`1915`	`1915`
`1916`	`1916`	`if (!repo_config_get_string(the_repository, "fetch.uriprotocols", &str) && str) {`
`1917`		`- string_list_split(&uri_protocols, str, ',', -1);`
	`1917`	`+ string_list_split(&uri_protocols, str, ",", -1);`
`1918`	`1918`	`free(str);`
`1919`	`1919`	`}`
`1920`	`1920`	`}`