[PATCH v2] utf8: use size_t for string width methods and callee sites.

utf8_strwidth() and utf8_strnwidth() return int, even though the
return value is always non-negative:

- utf8_strnwidth() accumulates the width into a size_t and otherwise
  returns its size_t len parameter,
- utf8_strwidth() just forwards its result.

Change their signatures to return size_t instead.

Update the types of the variables the said method is used to avoid
potential UB caused by implicit conversion from size_t to int.

The returned values from `utf8_strwidth()` are casted to int at places
where it was falling tests or required other changes.

Signed-off-by: Hardik Kumar <[email protected]>
---
Changes in v2:
- reworked types for utf8_strwidth and its sites of usage.
- removed redundant parens around `string`.
- updated commit message for better explaining the patch.

 builtin/blame.c  |  4 ++--
 builtin/branch.c |  2 +-
 builtin/repo.c   | 10 +++++-----
 column.c         |  2 +-
 diff.c           |  7 ++++---
 gettext.c        |  2 +-
 gettext.h        |  2 +-
 pretty.c         |  5 +++--
 utf8.c           | 13 ++++---------
 utf8.h           |  4 ++--
 wt-status.c      |  8 ++++----
 11 files changed, 28 insertions(+), 31 deletions(-)

diff --git a/builtin/blame.c b/builtin/blame.c
index 48d5251..2d24b63 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -564,7 +564,7 @@ static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent,
 					name = ci.author_mail.buf;
 				else
 					name = ci.author.buf;
-				pad = longest_author - utf8_strwidth(name);
+				pad = longest_author - cast_size_t_to_int(utf8_strwidth(name));
 				printf(" (%s%*s %10s",
 				       name, pad, "",
 				       format_time(ci.author_time,
@@ -668,7 +668,7 @@ static void find_alignment(struct blame_scoreboard *sb, int *option)
 
 	for (e = sb->ent; e; e = e->next) {
 		struct blame_origin *suspect = e->suspect;
-		int num;
+		size_t num;
 		size_t marks_count = count_marks(e, *option);
 
 		if (max_marks_count < marks_count)
diff --git a/builtin/branch.c b/builtin/branch.c
index dede60d..514ba64 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -354,7 +354,7 @@ static int calc_maxwidth(struct ref_array *refs, int remote_bonus)
 	for (i = 0; i < refs->nr; i++) {
 		struct ref_array_item *it = refs->items[i];
 		const char *desc = it->refname;
-		int w;
+		size_t w;
 
 		skip_prefix(it->refname, "refs/heads/", &desc);
 		skip_prefix(it->refname, "refs/remotes/", &desc);
diff --git a/builtin/repo.c b/builtin/repo.c
index 84e012f..47b9191 100644
--- a/builtin/repo.c
+++ b/builtin/repo.c
@@ -367,7 +367,7 @@ static void stats_table_vaddf(struct stats_table *table,
 	struct strbuf buf = STRBUF_INIT;
 	struct string_list_item *item;
 	char *formatted_name;
-	int name_width;
+	size_t name_width;
 
 	strbuf_vaddf(&buf, format, ap);
 	formatted_name = strbuf_detach(&buf, NULL);
@@ -387,12 +387,12 @@ static void stats_table_vaddf(struct stats_table *table,
 		string_list_append_nodup(&table->annotations, strbuf_detach(&buf, NULL));
 	}
 	if (entry->value) {
-		int value_width = utf8_strwidth(entry->value);
+		size_t value_width = utf8_strwidth(entry->value);
 		if (value_width > table->value_col_width)
 			table->value_col_width = value_width;
 	}
 	if (entry->unit) {
-		int unit_width = utf8_strwidth(entry->unit);
+		size_t unit_width = utf8_strwidth(entry->unit);
 		if (unit_width > table->unit_col_width)
 			table->unit_col_width = unit_width;
 	}
@@ -582,8 +582,8 @@ static void stats_table_print_structure(const struct stats_table *table)
 {
 	const char *name_col_title = _("Repository structure");
 	const char *value_col_title = _("Value");
-	int title_name_width = utf8_strwidth(name_col_title);
-	int title_value_width = utf8_strwidth(value_col_title);
+	size_t title_name_width = utf8_strwidth(name_col_title);
+	size_t title_value_width = utf8_strwidth(value_col_title);
 	int name_col_width = table->name_col_width;
 	int value_col_width = table->value_col_width;
 	int unit_col_width = table->unit_col_width;
diff --git a/column.c b/column.c
index 93fae31..6b7f921 100644
--- a/column.c
+++ b/column.c
@@ -24,7 +24,7 @@ struct column_data {
 };
 
 /* return length of 's' in letters, ANSI escapes stripped */
-static int item_length(const char *s)
+static size_t item_length(const char *s)
 {
 	return utf8_strnwidth(s, strlen(s), 1);
 }
diff --git a/diff.c b/diff.c
index 589c196..4887958 100644
--- a/diff.c
+++ b/diff.c
@@ -2952,7 +2952,8 @@ static int utf8_ish_width(const char **start)
 
 static void show_stats(struct diffstat_t *data, struct diff_options *options)
 {
-	int i, len, add, del, adds = 0, dels = 0;
+	int i, add, del, adds = 0, dels = 0;
+	size_t len;
 	uintmax_t max_change = 0, max_len = 0;
 	int total_files = data->nr, count;
 	int width, name_width, graph_width, number_width = 0, bin_width = 0;
@@ -3037,7 +3038,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
 	 * making the line longer than the maximum width.
 	 */
 	if (options->stat_width == -1)
-		width = term_columns() - utf8_strnwidth(line_prefix, strlen(line_prefix), 1);
+		width = term_columns() - cast_size_t_to_int(utf8_strnwidth(line_prefix, strlen(line_prefix), 1));
 	else
 		width = options->stat_width ? options->stat_width : 80;
 	number_width = decimal_width(max_change) > number_width ?
@@ -3123,7 +3124,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
 			if (slash)
 				name = slash;
 		}
-		padding = len - utf8_strwidth(name);
+		padding = len - cast_size_t_to_int(utf8_strwidth(name));
 		if (padding < 0)
 			padding = 0;
 
diff --git a/gettext.c b/gettext.c
index 8d08a61..4d5d05e 100644
--- a/gettext.c
+++ b/gettext.c
@@ -129,7 +129,7 @@ void git_setup_gettext(void)
 }
 
 /* return the number of columns of string 's' in current locale */
-int gettext_width(const char *s)
+size_t gettext_width(const char *s)
 {
 	static int is_utf8 = -1;
 	if (is_utf8 == -1)
diff --git a/gettext.h b/gettext.h
index 484cafa..f161a21 100644
--- a/gettext.h
+++ b/gettext.h
@@ -31,7 +31,7 @@
 #ifndef NO_GETTEXT
 extern int git_gettext_enabled;
 void git_setup_gettext(void);
-int gettext_width(const char *s);
+size_t gettext_width(const char *s);
 #else
 #define git_gettext_enabled (0)
 static inline void git_setup_gettext(void)
diff --git a/pretty.c b/pretty.c
index d8a9f37..f7d392d 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1805,11 +1805,12 @@ static size_t format_and_pad_commit(struct strbuf *sb, /* in UTF-8 */
 {
 	struct strbuf local_sb = STRBUF_INIT;
 	size_t total_consumed = 0;
-	int len, padding = c->padding;
+	int padding = c->padding;
+	size_t len;
 
 	if (padding < 0) {
 		const char *start = strrchr(sb->buf, '\n');
-		int occupied;
+		size_t occupied;
 		if (!start)
 			start = sb->buf;
 		occupied = utf8_strnwidth(start, strlen(start), 1);
diff --git a/utf8.c b/utf8.c
index 96460cc..cefaefe 100644
--- a/utf8.c
+++ b/utf8.c
@@ -208,7 +208,7 @@ int utf8_width(const char **start, size_t *remainder_p)
  * string, assuming that the string is utf8.  Returns strlen() instead
  * if the string does not look like a valid utf8 string.
  */
-int utf8_strnwidth(const char *string, size_t len, int skip_ansi)
+size_t utf8_strnwidth(const char *string, size_t len, int skip_ansi)
 {
 	const char *orig = string;
 	size_t width = 0;
@@ -225,15 +225,10 @@ int utf8_strnwidth(const char *string, size_t len, int skip_ansi)
 		if (glyph_width > 0)
 			width += glyph_width;
 	}
-
-	/*
-	 * TODO: fix the interface of this function and `utf8_strwidth()` to
-	 * return `size_t` instead of `int`.
-	 */
-	return cast_size_t_to_int(string ? width : len);
+	return string ? width : len;
 }
 
-int utf8_strwidth(const char *string)
+size_t utf8_strwidth(const char *string)
 {
 	return utf8_strnwidth(string, strlen(string), 0);
 }
@@ -821,7 +816,7 @@ void strbuf_utf8_align(struct strbuf *buf, align_type position, unsigned int wid
 		       const char *s)
 {
 	size_t slen = strlen(s);
-	int display_len = utf8_strnwidth(s, slen, 0);
+	size_t display_len = utf8_strnwidth(s, slen, 0);
 	int utf8_compensation = slen - display_len;
 
 	if (display_len >= width) {
diff --git a/utf8.h b/utf8.h
index cf8ecb0..531e968 100644
--- a/utf8.h
+++ b/utf8.h
@@ -7,8 +7,8 @@ typedef unsigned int ucs_char_t;  /* assuming 32bit int */
 
 size_t display_mode_esc_sequence_len(const char *s);
 int utf8_width(const char **start, size_t *remainder_p);
-int utf8_strnwidth(const char *string, size_t len, int skip_ansi);
-int utf8_strwidth(const char *string);
+size_t utf8_strnwidth(const char *string, size_t len, int skip_ansi);
+size_t utf8_strwidth(const char *string);
 int is_utf8(const char *text);
 int is_encoding_utf8(const char *name);
 int same_encoding(const char *, const char *);
diff --git a/wt-status.c b/wt-status.c
index 58461e0..0e1e32d 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -331,9 +331,9 @@ static int maxwidth(const char *(*label)(int), int minval, int maxval)
 
 	for (i = minval; i <= maxval; i++) {
 		const char *s = label(i);
-		int len = s ? utf8_strwidth(s) : 0;
+		size_t len = s ? utf8_strwidth(s) : 0;
 		if (len > result)
-			result = len;
+			result = cast_size_t_to_int(len);
 	}
 	return result;
 }
@@ -360,7 +360,7 @@ static void wt_longstatus_print_unmerged_data(struct wt_status *s,
 	status_printf(s, color(WT_STATUS_HEADER, s), "\t");
 
 	how = wt_status_unmerged_status_string(d->stagemask);
-	len = label_width - utf8_strwidth(how);
+	len = label_width - cast_size_t_to_int(utf8_strwidth(how));
 	status_printf_more(s, c, "%s%.*s%s\n", how, len, padding, one);
 	strbuf_release(&onebuf);
 }
@@ -429,7 +429,7 @@ static void wt_longstatus_print_change_data(struct wt_status *s,
 	what = wt_status_diff_status_string(status);
 	if (!what)
 		BUG("unhandled diff status %c", status);
-	len = label_width - utf8_strwidth(what);
+	len = label_width - cast_size_t_to_int(utf8_strwidth(what));
 	assert(len >= 0);
 	if (one_name != two_name)
 		status_printf_more(s, c, "%s%.*s%s -> %s",
-- 
2.55.0