From 62a51dead9eb7b5d6892447b11070bc8fab41c6a Mon Sep 17 00:00:00 2001
From: matt335672 <30179339+matt335672@users.noreply.github.com>
Date: Sun, 24 Dec 2023 20:14:14 +0000
Subject: [PATCH] Fix g_strtrim() regression

Commit 36ea4a3 failed to take UTF-8 characters into account on
platforms with signed char.
---
 common/string_calls.c            |  8 +++++---
 tests/common/test_string_calls.c | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/common/string_calls.c b/common/string_calls.c
index 16acc869..dca5bc15 100644
--- a/common/string_calls.c
+++ b/common/string_calls.c
@@ -715,6 +715,7 @@ g_strstr(const char *haystack, const char *needle)
 int
 g_strtrim(char *str, int trim_flags)
 {
+#define TRIMMABLE_CHAR(c) ((unsigned char)(c) <= ' ')
     int rv = 0;
     int index;
     int j;
@@ -726,7 +727,7 @@ g_strtrim(char *str, int trim_flags)
             j = 0;
             for (index = 0; str[index] != '\0'; index++)
             {
-                if (str[index] > ' ')
+                if (!TRIMMABLE_CHAR(str[index]))
                 {
                     str[j++] = str[index];
                 }
@@ -741,7 +742,7 @@ g_strtrim(char *str, int trim_flags)
 
         case 2: /* trim right */
             index = strlen(str);
-            while (index > 0 && str[index - 1] <= ' ')
+            while (index > 0 && TRIMMABLE_CHAR(str[index - 1]))
             {
                 --index;
             }
@@ -750,7 +751,7 @@ g_strtrim(char *str, int trim_flags)
 
         case 1: /* trim left */
             index = 0;
-            while (str[index] != '\0' && str[index] <= ' ')
+            while (str[index] != '\0' && TRIMMABLE_CHAR(str[index]))
             {
                 ++index;
             }
@@ -765,6 +766,7 @@ g_strtrim(char *str, int trim_flags)
     }
 
     return rv;
+#undef TRIMMABLE_CHAR
 }
 
 /*****************************************************************************/
diff --git a/tests/common/test_string_calls.c b/tests/common/test_string_calls.c
index 02240809..5944c536 100644
--- a/tests/common/test_string_calls.c
+++ b/tests/common/test_string_calls.c
@@ -14,6 +14,24 @@
 
 #define RESULT_LEN 1024
 
+/* Universal character names need a C99 compiler */
+#if __STDC_VERSION__ >= 199901L
+#   define CJK_UNIFIED_IDEOGRAPH_5E78 "\u5e78"
+#   define CJK_UNIFIED_IDEOGRAPH_798F "\u798f"
+#   define CJK_UNIFIED_IDEOGRAPH_5B89 "\u5b89"
+#   define CJK_UNIFIED_IDEOGRAPH_5EB7 "\u5eb7"
+#else
+// Assume we're using UTF-8
+#   define CJK_UNIFIED_IDEOGRAPH_5E78 "\xe5\xb9\xb8"
+#   define CJK_UNIFIED_IDEOGRAPH_798F "\xe7\xa6\x8f"
+#   define CJK_UNIFIED_IDEOGRAPH_5B89 "\xe5\xae\x89"
+#   define CJK_UNIFIED_IDEOGRAPH_5EB7 "\xe5\xba\xb7"
+#endif
+
+#define HAPPINESS_AND_WELL_BEING  \
+    CJK_UNIFIED_IDEOGRAPH_5E78 CJK_UNIFIED_IDEOGRAPH_798F \
+    CJK_UNIFIED_IDEOGRAPH_5B89 CJK_UNIFIED_IDEOGRAPH_5EB7
+
 START_TEST(test_strnjoin__when_src_is_null__returns_empty_string)
 {
     /* setup */
@@ -1038,6 +1056,19 @@ START_TEST(test_strtrim__trim_through)
 }
 END_TEST
 
+START_TEST(test_strtrim__chinese_chars)
+{
+    /* setup */
+    char output[] = "\t\t    \t" HAPPINESS_AND_WELL_BEING "\t\t    \n\n";
+
+    /* test */
+    g_strtrim(output, 4);
+
+    /* verify */
+    ck_assert_str_eq(output, HAPPINESS_AND_WELL_BEING);
+}
+END_TEST
+
 /******************************************************************************/
 
 START_TEST(test_sigs__common)
@@ -1192,6 +1223,7 @@ make_suite_test_string(void)
     tcase_add_test(tc_strtrim, test_strtrim__trim_right);
     tcase_add_test(tc_strtrim, test_strtrim__trim_both);
     tcase_add_test(tc_strtrim, test_strtrim__trim_through);
+    tcase_add_test(tc_strtrim, test_strtrim__chinese_chars);
 
     tc_sigs = tcase_create("signals");
     suite_add_tcase(s, tc_sigs);