5 files changed, 15 insertions, 7 deletions
diff --git a/source/blender/blenlib/BLI_string.h b/source/blender/blenlib/BLI_string.h
index 943597b6688..ba906e1221c 100644
--- a/source/blender/blenlib/BLI_string.h
+++ b/source/blender/blenlib/BLI_string.h
@@ -204,7 +204,7 @@ __attribute__((warn_unused_result))
 __attribute__((nonnull))
 #endif
 ;
-size_t BLI_strnlen(const char *str, size_t maxlen)
+size_t BLI_strnlen(const char *str, const size_t maxlen)
 #ifdef __GNUC__
 __attribute__((warn_unused_result))
 __attribute__((nonnull))
diff --git a/source/blender/blenlib/BLI_string_utf8.h b/source/blender/blenlib/BLI_string_utf8.h
index 20b56f85b53..73f138a750d 100644
--- a/source/blender/blenlib/BLI_string_utf8.h
+++ b/source/blender/blenlib/BLI_string_utf8.h
@@ -50,7 +50,7 @@ char        *BLI_str_prev_char_utf8(const char *p);
 /* wchar_t functions, copied from blenders own font.c originally */
 size_t       BLI_wstrlen_utf8(const wchar_t *src);
 size_t       BLI_strlen_utf8(const char *strc);
-size_t       BLI_strlen_range_utf8(const char *start, const char *end);
+size_t       BLI_strnlen_utf8(const char *start, const size_t maxlen);
 size_t       BLI_strncpy_wchar_as_utf8(char *__restrict dst, const wchar_t *__restrict src, const size_t maxcpy);
 size_t       BLI_strncpy_wchar_from_utf8(wchar_t *__restrict dst, const char *__restrict src, const size_t maxcpy);
 
diff --git a/source/blender/blenlib/intern/string.c b/source/blender/blenlib/intern/string.c
index 40b2fc20cfa..73d88ddd259 100644
--- a/source/blender/blenlib/intern/string.c
+++ b/source/blender/blenlib/intern/string.c
@@ -416,7 +416,7 @@ void BLI_timestr(double _time, char *str)
 }
 
 /* determine the length of a fixed-size string */
-size_t BLI_strnlen(const char *str, size_t maxlen)
+size_t BLI_strnlen(const char *str, const size_t maxlen)
 {
 	const char *end = memchr(str, '\0', maxlen);
 	return end ? (size_t) (end - str) : maxlen;
diff --git a/source/blender/blenlib/intern/string_utf8.c b/source/blender/blenlib/intern/string_utf8.c
index 7f6057dfdc4..5684b12cc8b 100644
--- a/source/blender/blenlib/intern/string_utf8.c
+++ b/source/blender/blenlib/intern/string_utf8.c
@@ -261,13 +261,21 @@ size_t BLI_strlen_utf8(const char *strc)
 	return len;
 }
 
-size_t BLI_strlen_range_utf8(const char *start, const char *end)
+/**
+ * \param start the string to measure the length.
+ * \param maxlen the string length (in bytes)
+ * \return the unicode length (not in bytes!)
+ */
+size_t BLI_strnlen_utf8(const char *start, const size_t maxlen)
 {
 	const char *strc = start;
-	int len;
+	const char *strc_end = start + maxlen;
 
-	for (len = 0; strc < end; len++)
+	size_t len;
+
+	for (len = 0; *strc && strc < strc_end; len++) {
 		strc += strlen_utf8_char(strc);
+	}
 
 	return len;
 }
diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index c903fd4186e..0b66c5564c6 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -1324,7 +1324,7 @@ static int ui_text_position_from_hidden(uiBut *but, int pos)
 
 static int ui_text_position_to_hidden(uiBut *but, int pos)
 {
-	return BLI_strlen_range_utf8(but->drawstr, but->drawstr + pos);
+	return BLI_strnlen_utf8(but->drawstr, pos);
 }
 
 void ui_button_text_password_hide(char password_str[UI_MAX_DRAW_STR], uiBut *but, int restore)