Added SDL_strnstr()

src/dynapi/SDL_dynapi.sym

@@ -960,6 +960,8 @@ SDL3_0.0.0 {
     SDL_GetGamepadMappings;
     SDL_GetTouchDevices;
     SDL_GetTouchDeviceName;
+    SDL_strnstr;
+    SDL_wcsnstr;
     # extra symbols go here (don't modify this line)
   local: *;
 };

src/dynapi/SDL_dynapi_overrides.h

@@ -985,3 +985,5 @@
 #define SDL_GetGamepadMappings SDL_GetGamepadMappings_REAL
 #define SDL_GetTouchDevices SDL_GetTouchDevices_REAL
 #define SDL_GetTouchDeviceName SDL_GetTouchDeviceName_REAL
+#define SDL_strnstr SDL_strnstr_REAL
+#define SDL_wcsnstr SDL_wcsnstr_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -1010,3 +1010,5 @@ SDL_DYNAPI_PROC(SDL_Renderer*,SDL_CreateRendererWithProperties,(SDL_PropertiesID
 SDL_DYNAPI_PROC(char**,SDL_GetGamepadMappings,(int *a),(a),return)
 SDL_DYNAPI_PROC(SDL_TouchID*,SDL_GetTouchDevices,(int *a),(a),return)
 SDL_DYNAPI_PROC(const char*,SDL_GetTouchDeviceName,(SDL_TouchID a),(a),return)
+SDL_DYNAPI_PROC(char*,SDL_strnstr,(const char *a, const char *b, size_t c),(a,b,c),return)
+SDL_DYNAPI_PROC(wchar_t*,SDL_wcsnstr,(const wchar_t *a, const wchar_t *b, size_t c),(a,b,c),return)

src/stdlib/SDL_string.c

@@ -468,19 +468,28 @@ wchar_t *SDL_wcsdup(const wchar_t *string)
     return newstr;
 }
 
+wchar_t *SDL_wcsnstr(const wchar_t *haystack, const wchar_t *needle, size_t maxlen)
+{
+    size_t length = SDL_wcslen(needle);
+    if (length == 0) {
+        return (wchar_t *)haystack;
+    }
+    while (maxlen >= length && *haystack) {
+        if (maxlen >= length && SDL_wcsncmp(haystack, needle, length) == 0) {
+            return (wchar_t *)haystack;
+        }
+        ++haystack;
+        --maxlen;
+    }
+    return NULL;
+}
+
 wchar_t *SDL_wcsstr(const wchar_t *haystack, const wchar_t *needle)
 {
 #ifdef HAVE_WCSSTR
     return SDL_const_cast(wchar_t *, wcsstr(haystack, needle));
 #else
-    size_t length = SDL_wcslen(needle);
-    while (*haystack) {
-        if (SDL_wcsncmp(haystack, needle, length) == 0) {
-            return (wchar_t *)haystack;
-        }
-        ++haystack;
-    }
-    return NULL;
+    return SDL_wcsnstr(haystack, needle, SDL_wcslen(haystack));
 #endif /* HAVE_WCSSTR */
 }
 
@@ -821,19 +830,32 @@ char *SDL_strrchr(const char *string, int c)
 #endif /* HAVE_STRRCHR */
 }
 
+char *SDL_strnstr(const char *haystack, const char *needle, size_t maxlen)
+{
+#ifdef HAVE_STRNSTR
+    return SDL_const_cast(char *, strnstr(haystack, needle, maxlen));
+#else
+    size_t length = SDL_strlen(needle);
+    if (length == 0) {
+        return (char *)haystack;
+    }
+    while (maxlen >= length && *haystack) {
+        if (SDL_strncmp(haystack, needle, length) == 0) {
+            return (char *)haystack;
+        }
+        ++haystack;
+        --maxlen;
+    }
+    return NULL;
+#endif /* HAVE_STRSTR */
+}
+
 char *SDL_strstr(const char *haystack, const char *needle)
 {
 #ifdef HAVE_STRSTR
     return SDL_const_cast(char *, strstr(haystack, needle));
 #else
-    size_t length = SDL_strlen(needle);
-    while (*haystack) {
-        if (SDL_strncmp(haystack, needle, length) == 0) {
-            return (char *)haystack;
-        }
-        ++haystack;
-    }
-    return NULL;
+    return SDL_strnstr(haystack, needle, SDL_strlen(haystack));
 #endif /* HAVE_STRSTR */
 }