Fix joystick user pointer NULL during disconnect

The joystick code did not distinguish between the allocation status of
the GLFW joystick object and whether it is connection to an OS level
joystick object.

These are now tracked separately.

Fixes #2092

CONTRIBUTORS.md

@@ -137,6 +137,7 @@ video tutorials.
  - Kenneth Miller
  - Bruce Mitchener
  - Jack Moffitt
+ - Ravi Mohan
  - Jeff Molofee
  - Alexander Monakov
  - Pierre Morel

README.md

@@ -174,6 +174,7 @@ information on what to include when reporting a bug.
  - Bugfix: Native access functions for context handles did not check that the API matched
  - Bugfix: `glfwMakeContextCurrent` would access TLS slot before initialization
  - Bugfix: `glfwSetGammaRamp` could emit `GLFW_INVALID_VALUE` before initialization
+ - Bugfix: `glfwGetJoystickUserPointer` returned `NULL` during disconnection (#2092)
  - [Win32] Added the `GLFW_WIN32_KEYBOARD_MENU` window hint for enabling access
            to the window menu
  - [Win32] Added a version info resource to the GLFW DLL

src/cocoa_joystick.m

@@ -96,8 +96,7 @@ static CFComparisonResult compareElements(const void* fp,
 //
 static void closeJoystick(_GLFWjoystick* js)
 {
-    if (!js->present)
-        return;
+    _glfwInputJoystick(js, GLFW_DISCONNECTED);
 
     for (int i = 0;  i < CFArrayGetCount(js->ns.axes);  i++)
         _glfw_free((void*) CFArrayGetValueAtIndex(js->ns.axes, i));
@@ -112,7 +111,6 @@ static void closeJoystick(_GLFWjoystick* js)
     CFRelease(js->ns.hats);
 
     _glfwFreeJoystick(js);
-    _glfwInputJoystick(js, GLFW_DISCONNECTED);
 }
 
 // Callback for user-initiated joystick addition
@@ -289,9 +287,9 @@ static void removeCallback(void* context,
 {
     for (int jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
     {
-        if (_glfw.joysticks[jid].ns.device == device)
+        if (_glfw.joysticks[jid].connected && _glfw.joysticks[jid].ns.device == device)
         {
-            closeJoystick(_glfw.joysticks + jid);
+            closeJoystick(&_glfw.joysticks[jid]);
             break;
         }
     }
@@ -382,7 +380,10 @@ GLFWbool _glfwInitJoysticksCocoa(void)
 void _glfwTerminateJoysticksCocoa(void)
 {
     for (int jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
-        closeJoystick(_glfw.joysticks + jid);
+    {
+        if (_glfw.joysticks[jid].connected)
+            closeJoystick(&_glfw.joysticks[jid]);
+    }
 
     if (_glfw.ns.hidManager)
     {
@@ -455,7 +456,7 @@ int _glfwPollJoystickCocoa(_GLFWjoystick* js, int mode)
         }
     }
 
-    return js->present;
+    return js->connected;
 }
 
 const char* _glfwGetMappingNameCocoa(void)

src/input.c

@@ -377,6 +377,11 @@ void _glfwInputJoystick(_GLFWjoystick* js, int event)
 {
     const int jid = (int) (js - _glfw.joysticks);
 
+    if (event == GLFW_CONNECTED)
+        js->connected = GLFW_TRUE;
+    else if (event == GLFW_DISCONNECTED)
+        js->connected = GLFW_FALSE;
+
     if (_glfw.callbacks.joystick)
         _glfw.callbacks.joystick(jid, event);
 }
@@ -442,7 +447,7 @@ _GLFWjoystick* _glfwAllocJoystick(const char* name,
 
     for (jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
     {
-        if (!_glfw.joysticks[jid].present)
+        if (!_glfw.joysticks[jid].allocated)
             break;
     }
 
@@ -450,7 +455,7 @@ _GLFWjoystick* _glfwAllocJoystick(const char* name,
         return NULL;
 
     js = _glfw.joysticks + jid;
-    js->present     = GLFW_TRUE;
+    js->allocated   = GLFW_TRUE;
     js->axes        = _glfw_calloc(axisCount, sizeof(float));
     js->buttons     = _glfw_calloc(buttonCount + (size_t) hatCount * 4, 1);
     js->hats        = _glfw_calloc(hatCount, 1);
@@ -972,7 +977,7 @@ GLFWAPI int glfwJoystickPresent(int jid)
         return GLFW_FALSE;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return GLFW_FALSE;
 
     return _glfw.platform.pollJoystick(js, _GLFW_POLL_PRESENCE);
@@ -1000,7 +1005,7 @@ GLFWAPI const float* glfwGetJoystickAxes(int jid, int* count)
         return NULL;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return NULL;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_AXES))
@@ -1032,7 +1037,7 @@ GLFWAPI const unsigned char* glfwGetJoystickButtons(int jid, int* count)
         return NULL;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return NULL;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_BUTTONS))
@@ -1068,7 +1073,7 @@ GLFWAPI const unsigned char* glfwGetJoystickHats(int jid, int* count)
         return NULL;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return NULL;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_BUTTONS))
@@ -1097,7 +1102,7 @@ GLFWAPI const char* glfwGetJoystickName(int jid)
         return NULL;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return NULL;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_PRESENCE))
@@ -1125,7 +1130,7 @@ GLFWAPI const char* glfwGetJoystickGUID(int jid)
         return NULL;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return NULL;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_PRESENCE))
@@ -1144,7 +1149,7 @@ GLFWAPI void glfwSetJoystickUserPointer(int jid, void* pointer)
     _GLFW_REQUIRE_INIT();
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->allocated)
         return;
 
     js->userPointer = pointer;
@@ -1160,7 +1165,7 @@ GLFWAPI void* glfwGetJoystickUserPointer(int jid)
     _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->allocated)
         return NULL;
 
     return js->userPointer;
@@ -1230,7 +1235,7 @@ GLFWAPI int glfwUpdateGamepadMappings(const char* string)
     for (jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
     {
         _GLFWjoystick* js = _glfw.joysticks + jid;
-        if (js->present)
+        if (js->connected)
             js->mapping = findValidMapping(js);
     }
 
@@ -1256,7 +1261,7 @@ GLFWAPI int glfwJoystickIsGamepad(int jid)
         return GLFW_FALSE;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return GLFW_FALSE;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_PRESENCE))
@@ -1284,7 +1289,7 @@ GLFWAPI const char* glfwGetGamepadName(int jid)
         return NULL;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return NULL;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_PRESENCE))
@@ -1319,7 +1324,7 @@ GLFWAPI int glfwGetGamepadState(int jid, GLFWgamepadstate* state)
         return GLFW_FALSE;
 
     js = _glfw.joysticks + jid;
-    if (!js->present)
+    if (!js->connected)
         return GLFW_FALSE;
 
     if (!_glfw.platform.pollJoystick(js, _GLFW_POLL_ALL))

src/internal.h

@@ -634,7 +634,8 @@ struct _GLFWmapping
 //
 struct _GLFWjoystick
 {
-    GLFWbool        present;
+    GLFWbool        allocated;
+    GLFWbool        connected;
     float*          axes;
     int             axisCount;
     unsigned char*  buttons;

src/linux_joystick.c

@@ -128,7 +128,7 @@ static GLFWbool openJoystickDevice(const char* path)
 {
     for (int jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
     {
-        if (!_glfw.joysticks[jid].present)
+        if (_glfw.joysticks[jid].connected)
             continue;
         if (strcmp(_glfw.joysticks[jid].linjs.path, path) == 0)
             return GLFW_FALSE;
@@ -245,9 +245,9 @@ static GLFWbool openJoystickDevice(const char* path)
 //
 static void closeJoystick(_GLFWjoystick* js)
 {
+    _glfwInputJoystick(js, GLFW_DISCONNECTED);
     close(js->linjs.fd);
     _glfwFreeJoystick(js);
-    _glfwInputJoystick(js, GLFW_DISCONNECTED);
 }
 
 // Lexically compare joysticks by name; used by qsort
@@ -366,7 +366,7 @@ void _glfwTerminateJoysticksLinux(void)
     for (int jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
     {
         _GLFWjoystick* js = _glfw.joysticks + jid;
-        if (js->present)
+        if (js->connected)
             closeJoystick(js);
     }
 
@@ -417,7 +417,7 @@ int _glfwPollJoystickLinux(_GLFWjoystick* js, int mode)
             handleAbsEvent(js, e.code, e.value);
     }
 
-    return js->present;
+    return js->connected;
 }
 
 const char* _glfwGetMappingNameLinux(void)

src/win32_joystick.c

@@ -256,6 +256,8 @@ static GLFWbool supportsXInput(const GUID* guid)
 //
 static void closeJoystick(_GLFWjoystick* js)
 {
+    _glfwInputJoystick(js, GLFW_DISCONNECTED);
+
     if (js->win32.device)
     {
         IDirectInputDevice8_Unacquire(js->win32.device);
@@ -263,9 +265,7 @@ static void closeJoystick(_GLFWjoystick* js)
     }
 
     _glfw_free(js->win32.objects);
-
     _glfwFreeJoystick(js);
-    _glfwInputJoystick(js, GLFW_DISCONNECTED);
 }
 
 // DirectInput device object enumeration callback
@@ -357,7 +357,7 @@ static BOOL CALLBACK deviceCallback(const DIDEVICEINSTANCE* di, void* user)
     for (jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
     {
         js = _glfw.joysticks + jid;
-        if (js->present)
+        if (js->connected)
         {
             if (memcmp(&js->win32.guid, &di->guidInstance, sizeof(GUID)) == 0)
                 return DIENUM_CONTINUE;
@@ -508,7 +508,7 @@ void _glfwDetectJoystickConnectionWin32(void)
 
             for (jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
             {
-                if (_glfw.joysticks[jid].present &&
+                if (_glfw.joysticks[jid].connected &&
                     _glfw.joysticks[jid].win32.device == NULL &&
                     _glfw.joysticks[jid].win32.index == index)
                 {
@@ -560,7 +560,7 @@ void _glfwDetectJoystickDisconnectionWin32(void)
     for (jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
     {
         _GLFWjoystick* js = _glfw.joysticks + jid;
-        if (js->present)
+        if (js->connected)
             _glfwPollJoystickWin32(js, _GLFW_POLL_PRESENCE);
     }
 }