Try matching game controller mappings on CRC and version and fall back to no CRC and no version, in that order.

We do exact match when adding mappings, but loose matching everywhere else we look up a mapping for a GUID.

src/joystick/SDL_gamecontroller.c

@@ -43,10 +43,16 @@
 /* Many controllers turn the center button into an instantaneous button press */
 #define SDL_MINIMUM_GUIDE_BUTTON_DELAY_MS   250
 
-#define SDL_CONTROLLER_PLATFORM_FIELD   "platform:"
-#define SDL_CONTROLLER_HINT_FIELD       "hint:"
-#define SDL_CONTROLLER_SDKGE_FIELD      "sdk>=:"
-#define SDL_CONTROLLER_SDKLE_FIELD      "sdk<=:"
+#define SDL_CONTROLLER_CRC_FIELD            "crc:"
+#define SDL_CONTROLLER_CRC_FIELD_SIZE       4 /* hard-coded for speed */
+#define SDL_CONTROLLER_PLATFORM_FIELD       "platform:"
+#define SDL_CONTROLLER_PLATFORM_FIELD_SIZE  SDL_strlen(SDL_CONTROLLER_PLATFORM_FIELD)
+#define SDL_CONTROLLER_HINT_FIELD           "hint:"
+#define SDL_CONTROLLER_HINT_FIELD_SIZE      SDL_strlen(SDL_CONTROLLER_HINT_FIELD)
+#define SDL_CONTROLLER_SDKGE_FIELD          "sdk>=:"
+#define SDL_CONTROLLER_SDKGE_FIELD_SIZE     SDL_strlen(SDL_CONTROLLER_SDKGE_FIELD)
+#define SDL_CONTROLLER_SDKLE_FIELD          "sdk<=:"
+#define SDL_CONTROLLER_SDKLE_FIELD_SIZE     SDL_strlen(SDL_CONTROLLER_SDKLE_FIELD)
 
 /* a list of currently opened game controllers */
 static SDL_GameController *SDL_gamecontrollers = NULL;
@@ -681,83 +687,101 @@ static ControllerMapping_t *SDL_CreateMappingForWGIController(SDL_JoystickGUID g
 /*
  * Helper function to scan the mappings database for a controller with the specified GUID
  */
-static ControllerMapping_t *SDL_PrivateGetControllerMappingForGUID(SDL_JoystickGUID guid, SDL_bool exact_match)
+static ControllerMapping_t *SDL_PrivateMatchControllerMappingForGUID(SDL_JoystickGUID guid, SDL_bool match_crc, SDL_bool match_version)
 {
     ControllerMapping_t *mapping;
-    Uint16 crc;
+    Uint16 crc = 0;
 
-    SDL_GetJoystickGUIDInfo(guid, NULL, NULL, NULL, &crc);
-    if (crc) {
-        /* Clear the CRC from the GUID for matching */
-        SDL_SetJoystickGUIDCRC(&guid, 0);
+    if (match_crc) {
+        SDL_GetJoystickGUIDInfo(guid, NULL, NULL, NULL, &crc);
+    }
+
+    /* Clear the CRC from the GUID for matching, the mappings never include it in the GUID */
+    SDL_SetJoystickGUIDCRC(&guid, 0);
+
+    if (!match_version) {
+        SDL_SetJoystickGUIDVersion(&guid, 0);
     }
+
     for (mapping = s_pSupportedControllers; mapping; mapping = mapping->next) {
-        if (SDL_memcmp(&guid, &mapping->guid, sizeof(guid)) == 0) {
-            /* Check to see if the CRC matches */
-            const char *crc_string = SDL_strstr(mapping->mapping, "crc:");
+        SDL_JoystickGUID mapping_guid;
+
+        SDL_memcpy(&mapping_guid, &mapping->guid, sizeof(mapping_guid));
+        if (!match_version) {
+            SDL_SetJoystickGUIDVersion(&mapping_guid, 0);
+        }
+
+        if (SDL_memcmp(&guid, &mapping_guid, sizeof(guid)) == 0) {
+            Uint16 mapping_crc = 0;
+            const char *crc_string = SDL_strstr(mapping->mapping, SDL_CONTROLLER_CRC_FIELD);
             if (crc_string) {
-                Uint16 mapping_crc = (Uint16)SDL_strtol(crc_string + 4, NULL, 16); 
-                if (crc != mapping_crc) {
-                    continue;
-                }
+                mapping_crc = (Uint16)SDL_strtol(crc_string + SDL_CONTROLLER_CRC_FIELD_SIZE, NULL, 16); 
+            }
+            if (crc == mapping_crc) {
+                return mapping;
             }
-            return mapping;
         }
     }
+    return NULL;
+}
 
-    if (!exact_match) {
-        /* Try again, ignoring the version */
-        Uint16 vendor, product;
-
-        SDL_GetJoystickGUIDInfo(guid, &vendor, &product, NULL, NULL);
-        if (vendor && product) {
-            SDL_JoystickGUID match_guid;
-
-            SDL_memcpy(&match_guid, &guid, sizeof(guid));
-            SDL_SetJoystickGUIDVersion(&match_guid, 0);
+/*
+ * Helper function to scan the mappings database for a controller with the specified GUID
+ */
+static ControllerMapping_t *SDL_PrivateGetControllerMappingForGUID(SDL_JoystickGUID guid)
+{
+    ControllerMapping_t *mapping;
+    Uint16 vendor, product, crc;
 
-            for (mapping = s_pSupportedControllers; mapping; mapping = mapping->next) {
-                SDL_JoystickGUID mapping_guid;
+    SDL_GetJoystickGUIDInfo(guid, &vendor, &product, NULL, &crc);
+    if (crc) {
+        /* First check for exact CRC matching */
+        mapping = SDL_PrivateMatchControllerMappingForGUID(guid, SDL_TRUE, SDL_TRUE);
+        if (mapping) {
+            return mapping;
+        }
+    }
 
-                SDL_memcpy(&mapping_guid, &mapping->guid, sizeof(mapping_guid));
-                SDL_SetJoystickGUIDVersion(&mapping_guid, 0);
+    /* Now check for a mapping without CRC */
+    mapping = SDL_PrivateMatchControllerMappingForGUID(guid, SDL_FALSE, SDL_TRUE);
+    if (mapping) {
+        return mapping;
+    }
 
-                if (SDL_memcmp(&match_guid, &mapping_guid, sizeof(match_guid)) == 0) {
-                    /* Check to see if the CRC matches */
-                    const char *crc_string = SDL_strstr(mapping->mapping, "crc:");
-                    if (crc_string) {
-                        Uint16 mapping_crc = (Uint16)SDL_strtol(crc_string + 4, NULL, 16); 
-                        if (crc != mapping_crc) {
-                            continue;
-                        }
-                    }
-                    return mapping;
-                }
+    if (vendor && product) {
+        /* Try again, ignoring the version */
+        if (crc) {
+            mapping = SDL_PrivateMatchControllerMappingForGUID(guid, SDL_TRUE, SDL_FALSE);
+            if (mapping) {
+                return mapping;
             }
         }
+
+        mapping = SDL_PrivateMatchControllerMappingForGUID(guid, SDL_FALSE, SDL_FALSE);
+        if (mapping) {
+            return mapping;
+        }
     }
 
-    if (!exact_match) {
 #if SDL_JOYSTICK_XINPUT
-        if (SDL_IsJoystickXInput(guid)) {
-            /* This is an XInput device */
-            return s_pXInputMapping;
-        }
+    if (SDL_IsJoystickXInput(guid)) {
+        /* This is an XInput device */
+        return s_pXInputMapping;
+    }
 #endif
-        if (!mapping) {
-            if (SDL_IsJoystickHIDAPI(guid)) {
-                mapping = SDL_CreateMappingForHIDAPIController(guid);
-            } else if (SDL_IsJoystickRAWINPUT(guid)) {
-                mapping = SDL_CreateMappingForRAWINPUTController(guid);
-            } else if (SDL_IsJoystickWGI(guid)) {
-                mapping = SDL_CreateMappingForWGIController(guid);
-            } else if (SDL_IsJoystickVirtual(guid)) {
-                /* We'll pick up a robust mapping in VIRTUAL_JoystickGetGamepadMapping */
+    if (!mapping) {
+        if (SDL_IsJoystickHIDAPI(guid)) {
+            mapping = SDL_CreateMappingForHIDAPIController(guid);
+        } else if (SDL_IsJoystickRAWINPUT(guid)) {
+            mapping = SDL_CreateMappingForRAWINPUTController(guid);
+        } else if (SDL_IsJoystickWGI(guid)) {
+            mapping = SDL_CreateMappingForWGIController(guid);
+        } else if (SDL_IsJoystickVirtual(guid)) {
+            /* We'll pick up a robust mapping in VIRTUAL_JoystickGetGamepadMapping */
 #ifdef __ANDROID__
-            } else {
-                mapping = SDL_CreateMappingForAndroidController(guid);
+        } else {
+            mapping = SDL_CreateMappingForAndroidController(guid);
 #endif
-            }
         }
     }
     return mapping;
@@ -1179,7 +1203,7 @@ SDL_PrivateAddMappingForGUID(SDL_JoystickGUID jGUID, const char *mappingString,
         /* Make sure the mapping has the CRC */
         char *new_mapping;
         char *crc_end = "";
-        char *crc_string = SDL_strstr(pchMapping, "crc:");
+        char *crc_string = SDL_strstr(pchMapping, SDL_CONTROLLER_CRC_FIELD);
         if (crc_string) {
             crc_end = SDL_strchr(crc_string, ',');
             if (crc_end) {
@@ -1190,22 +1214,22 @@ SDL_PrivateAddMappingForGUID(SDL_JoystickGUID jGUID, const char *mappingString,
             *crc_string = '\0';
         }
 
-        if (SDL_asprintf(&new_mapping, "%scrc:%.4x,%s", pchMapping, crc, crc_end) >= 0) {
+        if (SDL_asprintf(&new_mapping, "%s%s%.4x,%s", pchMapping, SDL_CONTROLLER_CRC_FIELD, crc, crc_end) >= 0) {
             SDL_free(pchMapping);
             pchMapping = new_mapping;
         }
     } else {
         /* Make sure the GUID has the CRC, for matching purposes */
-        char *crc_string = SDL_strstr(pchMapping, "crc:");
+        char *crc_string = SDL_strstr(pchMapping, SDL_CONTROLLER_CRC_FIELD);
         if (crc_string) {
-            crc = (Uint16)SDL_strtol(crc_string + 4, NULL, 16);
+            crc = (Uint16)SDL_strtol(crc_string + SDL_CONTROLLER_CRC_FIELD_SIZE, NULL, 16);
             if (crc) {
                 SDL_SetJoystickGUIDCRC(&jGUID, crc);
             }
         }
     }
 
-    pControllerMapping = SDL_PrivateGetControllerMappingForGUID(jGUID, SDL_TRUE);
+    pControllerMapping = SDL_PrivateMatchControllerMappingForGUID(jGUID, SDL_TRUE, SDL_TRUE);
     if (pControllerMapping) {
         /* Only overwrite the mapping if the priority is the same or higher. */
         if (pControllerMapping->priority <= priority) {
@@ -1265,7 +1289,7 @@ static ControllerMapping_t *SDL_PrivateGetControllerMappingForNameAndGUID(const
 {
     ControllerMapping_t *mapping;
 
-    mapping = SDL_PrivateGetControllerMappingForGUID(guid, SDL_FALSE);
+    mapping = SDL_PrivateGetControllerMappingForGUID(guid);
 #ifdef __LINUX__
     if (!mapping && name) {
         if (SDL_strstr(name, "Xbox 360 Wireless Receiver")) {
@@ -1456,7 +1480,7 @@ SDL_GameControllerAddMappingsFromRW(SDL_RWops * rw, int freerw)
         /* Extract and verify the platform */
         tmp = SDL_strstr(line, SDL_CONTROLLER_PLATFORM_FIELD);
         if (tmp != NULL) {
-            tmp += SDL_strlen(SDL_CONTROLLER_PLATFORM_FIELD);
+            tmp += SDL_CONTROLLER_PLATFORM_FIELD_SIZE;
             comma = SDL_strchr(tmp, ',');
             if (comma != NULL) {
                 platform_len = comma - tmp + 1;
@@ -1503,7 +1527,7 @@ SDL_PrivateGameControllerAddMapping(const char *mappingString, SDL_ControllerMap
             int len;
             char hint[128];
 
-            tmp += SDL_strlen(SDL_CONTROLLER_HINT_FIELD);
+            tmp += SDL_CONTROLLER_HINT_FIELD_SIZE;
 
             if (*tmp == '!') {
                 negate = SDL_TRUE;
@@ -1541,14 +1565,14 @@ SDL_PrivateGameControllerAddMapping(const char *mappingString, SDL_ControllerMap
 
         tmp = SDL_strstr(mappingString, SDL_CONTROLLER_SDKGE_FIELD);
         if (tmp != NULL) {
-            tmp += SDL_strlen(SDL_CONTROLLER_SDKGE_FIELD);
+            tmp += SDL_CONTROLLER_SDKGE_FIELD_SIZE;
             if (!(SDL_GetAndroidSDKVersion() >= SDL_atoi(tmp))) {
                 return SDL_SetError("SDK version %d < minimum version %d", SDL_GetAndroidSDKVersion(), SDL_atoi(tmp));
             }
         }
         tmp = SDL_strstr(mappingString, SDL_CONTROLLER_SDKLE_FIELD);
         if (tmp != NULL) {
-            tmp += SDL_strlen(SDL_CONTROLLER_SDKLE_FIELD);
+            tmp += SDL_CONTROLLER_SDKLE_FIELD_SIZE;
             if (!(SDL_GetAndroidSDKVersion() <= SDL_atoi(tmp))) {
                 return SDL_SetError("SDK version %d > maximum version %d", SDL_GetAndroidSDKVersion(), SDL_atoi(tmp));
             }
@@ -1633,7 +1657,7 @@ CreateMappingString(ControllerMapping_t *mapping, SDL_JoystickGUID guid)
         if (mapping->mapping[SDL_strlen(mapping->mapping) - 1] != ',') {
             needed += 1;
         }
-        needed += SDL_strlen(SDL_CONTROLLER_PLATFORM_FIELD) + SDL_strlen(platform);
+        needed += SDL_CONTROLLER_PLATFORM_FIELD_SIZE + SDL_strlen(platform);
     }
 
     pMappingString = SDL_malloc(needed);
@@ -1690,7 +1714,7 @@ SDL_GameControllerMappingForIndex(int mapping_index)
 char *
 SDL_GameControllerMappingForGUID(SDL_JoystickGUID guid)
 {
-    ControllerMapping_t *mapping = SDL_PrivateGetControllerMappingForGUID(guid, SDL_FALSE);
+    ControllerMapping_t *mapping = SDL_PrivateGetControllerMappingForGUID(guid);
     if (mapping) {
         return CreateMappingString(mapping, guid);
     } else {