From f649f69effb3653e618f487943dfe12f7ed809b1 Mon Sep 17 00:00:00 2001
From: matt335672 <30179339+matt335672@users.noreply.github.com>
Date: Wed, 20 Sep 2023 15:04:41 +0100
Subject: [PATCH] Remove mbstowcs/wcstombs from g_strtrim()

Because of the way UTF-8 encoding works, there is no need to
use mbstowcs/wcstombs in teh implementationof this function.
---
 common/string_calls.c | 132 ++++++++----------------------------------
 common/string_calls.h |   7 +++
 2 files changed, 31 insertions(+), 108 deletions(-)

diff --git a/common/string_calls.c b/common/string_calls.c
index 22a04a0a45..112da0fbfe 100644
--- a/common/string_calls.c
+++ b/common/string_calls.c
@@ -736,143 +736,59 @@ g_wcstombs(char *dest, const twchar *src, int n)
 
 /*****************************************************************************/
 /* returns error */
-/* trim spaces and tabs, anything <= space */
-/* trim_flags 1 trim left, 2 trim right, 3 trim both, 4 trim through */
-/* this will always shorten the string or not change it */
 int
 g_strtrim(char *str, int trim_flags)
 {
+    int rv = 0;
     int index;
-    int len;
-    int text1_index;
-    int got_char;
-    wchar_t *text;
-    wchar_t *text1;
-
-    len = mbstowcs(0, str, 0);
-
-    if (len < 1)
-    {
-        return 0;
-    }
-
-    if ((trim_flags < 1) || (trim_flags > 4))
-    {
-        return 1;
-    }
-
-    text = (wchar_t *)malloc(len * sizeof(wchar_t) + 8);
-    text1 = (wchar_t *)malloc(len * sizeof(wchar_t) + 8);
-    if (text == NULL || text1 == NULL)
-    {
-        free(text);
-        free(text1);
-        return 1;
-    }
-    text1_index = 0;
-    mbstowcs(text, str, len + 1);
+    int j;
 
     switch (trim_flags)
     {
         case 4: /* trim through */
 
-            for (index = 0; index < len; index++)
+            j = 0;
+            for (index = 0; str[index] != '\0'; index++)
             {
-                if (text[index] > 32)
+                if (str[index] > ' ')
                 {
-                    text1[text1_index] = text[index];
-                    text1_index++;
+                    str[j++] = str[index];
                 }
             }
 
-            text1[text1_index] = 0;
+            str[j] = '\0';
             break;
-        case 3: /* trim both */
-            got_char = 0;
 
-            for (index = 0; index < len; index++)
-            {
-                if (got_char)
-                {
-                    text1[text1_index] = text[index];
-                    text1_index++;
-                }
-                else
-                {
-                    if (text[index] > 32)
-                    {
-                        text1[text1_index] = text[index];
-                        text1_index++;
-                        got_char = 1;
-                    }
-                }
-            }
-
-            text1[text1_index] = 0;
-            len = text1_index;
+        case 3: /* trim both */
+            rv = g_strtrim(str, 1) || g_strtrim(str, 2);
+            break;
 
-            /* trim right */
-            for (index = len - 1; index >= 0; index--)
+        case 2: /* trim right */
+            index = strlen(str);
+            while (index > 0 && str[index - 1] <= ' ')
             {
-                if (text1[index] > 32)
-                {
-                    break;
-                }
+                --index;
             }
-
-            text1_index = index + 1;
-            text1[text1_index] = 0;
+            str[index] = '\0';
             break;
-        case 2: /* trim right */
 
-            /* copy it */
-            for (index = 0; index < len; index++)
+        case 1: /* trim left */
+            index = 0;
+            while (str[index] != '\0' && str[index] <= ' ')
             {
-                text1[text1_index] = text[index];
-                text1_index++;
+                ++index;
             }
-
-            /* trim right */
-            for (index = len - 1; index >= 0; index--)
+            if (index > 0)
             {
-                if (text1[index] > 32)
-                {
-                    break;
-                }
+                memmove(str, str + index, strlen(str) + 1 - index);
             }
-
-            text1_index = index + 1;
-            text1[text1_index] = 0;
             break;
-        case 1: /* trim left */
-            got_char = 0;
 
-            for (index = 0; index < len; index++)
-            {
-                if (got_char)
-                {
-                    text1[text1_index] = text[index];
-                    text1_index++;
-                }
-                else
-                {
-                    if (text[index] > 32)
-                    {
-                        text1[text1_index] = text[index];
-                        text1_index++;
-                        got_char = 1;
-                    }
-                }
-            }
-
-            text1[text1_index] = 0;
-            break;
+        default:
+            rv = 1;
     }
 
-    wcstombs(str, text1, text1_index + 1);
-    free(text);
-    free(text1);
-    return 0;
+    return rv;
 }
 
 /*****************************************************************************/
diff --git a/common/string_calls.h b/common/string_calls.h
index 46f3bbfc49..352ebc6b99 100644
--- a/common/string_calls.h
+++ b/common/string_calls.h
@@ -308,6 +308,13 @@ int      g_pos(const char *str, const char *to_find);
 char    *g_strstr(const char *haystack, const char *needle);
 int      g_mbstowcs(twchar *dest, const char *src, int n);
 int      g_wcstombs(char *dest, const twchar *src, int n);
+
+/** trim spaces and tabs, anything <= space
+ *
+ * @param str (assumed to be UTF-8)
+ * @param trim_flags 1 trim left, 2 trim right, 3 trim both, 4 trim through
+ * @return != 0 - trim_flags not recognised
+ * this will always shorten the string or not change it */
 int      g_strtrim(char *str, int trim_flags);
 
 /**