static analysis: Fixed several complaints from codechecker.

There are still some pending Objective-C specific issues.

Reference issue #4600.

src/SDL.c

@@ -316,6 +316,8 @@ SDL_InitSubSystem(Uint32 flags)
 #endif
     }
 
+    (void) flags_initialized;  /* make static analysis happy, since this only gets used in error cases. */
+
     return (0);
 
 quit_and_error:

src/audio/SDL_wave.c

@@ -685,7 +685,7 @@ MS_ADPCM_Decode(WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
 
     state.output.pos = 0;
     state.output.size = outputsize / sizeof(Sint16);
-    state.output.data = (Sint16 *)SDL_malloc(outputsize);
+    state.output.data = (Sint16 *)SDL_calloc(1, outputsize);
     if (state.output.data == NULL) {
         return SDL_OutOfMemory();
     }

src/events/SDL_mouse.c

@@ -384,8 +384,6 @@ SDL_PrivateSendMouseMotion(SDL_Window * window, SDL_MouseID mouseID, int relativ
 
     /* Ignore relative motion when first positioning the mouse */
     if (!mouse->has_position) {
-        xrel = 0;
-        yrel = 0;
         mouse->x = x;
         mouse->y = y;
         mouse->has_position = SDL_TRUE;

src/hidapi/mac/hid.c

@@ -572,7 +572,6 @@ struct hid_device_info  HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
 		if ((vendor_id == 0x0 && product_id == 0x0) ||
 		    (vendor_id == dev_vid && product_id == dev_pid)) {
 			struct hid_device_info *tmp;
-			size_t len;
 
 			/* VID/PID match. Create the record. */
 			tmp = (struct hid_device_info *)calloc(1, sizeof(struct hid_device_info));
@@ -590,7 +589,7 @@ struct hid_device_info  HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
 			
 			/* Fill out the record */
 			cur_dev->next = NULL;
-			len = make_path(dev, cbuf, sizeof(cbuf));
+			make_path(dev, cbuf, sizeof(cbuf));
 			cur_dev->path = strdup(cbuf);
 			
 			/* Serial Number */
@@ -817,10 +816,9 @@ hid_device * HID_API_EXPORT hid_open_path(const char *path, int bExclusive)
 	CFSetGetValues(device_set, (const void **) device_array);	
 	for (i = 0; i < num_devices; i++) {
 		char cbuf[BUF_LEN];
-		size_t len;
 		IOHIDDeviceRef os_dev = device_array[i];
 		
-		len = make_path(os_dev, cbuf, sizeof(cbuf));
+		make_path(os_dev, cbuf, sizeof(cbuf));
 		if (!strcmp(cbuf, path)) {
 			// Matched Paths. Open this Device.
 			IOReturn ret = IOHIDDeviceOpen(os_dev, kIOHIDOptionsTypeNone);
@@ -833,6 +831,7 @@ hid_device * HID_API_EXPORT hid_open_path(const char *path, int bExclusive)
 				
 				/* Create the buffers for receiving data */
 				dev->max_input_report_len = (CFIndex) get_max_report_length(os_dev);
+				SDL_assert(dev->max_input_report_len > 0);
 				dev->input_report_buf = (uint8_t *)calloc(dev->max_input_report_len, sizeof(uint8_t));
 				
 				/* Create the Run Loop Mode for this device.
@@ -936,11 +935,14 @@ static int return_data(hid_device *dev, unsigned char *data, size_t length)
 	/* Copy the data out of the linked list item (rpt) into the
 	 return buffer (data), and delete the liked list item. */
 	struct input_report *rpt = dev->input_reports;
-	size_t len = (length < rpt->len)? length: rpt->len;
+	size_t len = 0;
+	if (rpt != NULL) {
+		len = (length < rpt->len)? length: rpt->len;
 		memcpy(data, rpt->data, len);
 		dev->input_reports = rpt->next;
 		free(rpt->data);
 		free(rpt);
+	}
 	return (int)len;
 }
 

src/joystick/SDL_joystick.c

@@ -1590,11 +1590,13 @@ SDL_JoystickUpdate(void)
 
     for (joystick = SDL_joysticks; joystick; joystick = joystick->next) {
         if (joystick->attached) {
-            /* This should always be true, but seeing a crash in the wild...? */
+            /* This driver should always be != NULL, but seeing a crash in the wild...? */
-            if (joystick->driver) {
+            if (!joystick->driver) {
-                joystick->driver->Update(joystick);
+                continue;  /* nothing we can do, and other things use joystick->driver below here. */
             }
 
+            joystick->driver->Update(joystick);
+
             if (joystick->delayed_guide_button) {
                 SDL_GameControllerHandleDelayedGuideButton(joystick);
             }

src/joystick/hidapi/SDL_hidapijoystick.c

@@ -227,7 +227,7 @@ HIDAPI_CleanupDeviceDriver(SDL_HIDAPI_Device *device)
     }
 
     /* Disconnect any joysticks */
-    while (device->num_joysticks) {
+    while (device->num_joysticks && device->joysticks) {
         HIDAPI_JoystickDisconnected(device, device->joysticks[0]);
     }
 

src/render/SDL_render.c

@@ -3145,9 +3145,10 @@ SDL_RenderDrawLinesF(SDL_Renderer * renderer,
                     num_vertices, indices, num_indices, size_indices,
                     1.0f, 1.0f);
 
+        }
+
         SDL_small_free(xy, isstack1);
         SDL_small_free(indices, isstack2);
-        }
 
     } else if (renderer->scale.x != 1.0f || renderer->scale.y != 1.0f) {
         retval = RenderDrawLinesWithRectsF(renderer, points, count);

src/video/SDL_bmp.c

@@ -394,6 +394,12 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
         break;
     }
 
+    if (biBitCount >= 32) {  /* we shift biClrUsed by this value later. */
+        SDL_SetError("Unsupported or incorrect biBitCount field");
+        was_error = SDL_TRUE;
+        goto done;
+    }
+
     /* Create a compatible surface, note that the colors are RGB ordered */
     surface =
         SDL_CreateRGBSurface(0, biWidth, biHeight, biBitCount, Rmask, Gmask,

src/video/SDL_egl.c

@@ -530,7 +530,7 @@ SDL_EGL_LoadLibrary(_THIS, const char *egl_path, NativeDisplayType native_displa
     }
 #endif
     /* Try the implementation-specific eglGetDisplay even if eglGetPlatformDisplay fails */
-    if (_this->egl_data->egl_display == EGL_NO_DISPLAY) {
+    if ((_this->egl_data->egl_display == EGL_NO_DISPLAY) && (_this->egl_data->eglGetDisplay != NULL)) {
         _this->egl_data->egl_display = _this->egl_data->eglGetDisplay(native_display);
     }
     if (_this->egl_data->egl_display == EGL_NO_DISPLAY) {

src/video/SDL_video.c

@@ -261,6 +261,7 @@ SDL_CreateWindowTexture(SDL_VideoDevice *_this, SDL_Window * window, Uint32 * fo
                                       SDL_TEXTUREACCESS_STREAMING,
                                       window->w, window->h);
     if (!data->texture) {
+        /* codechecker_false_positive [Malloc] Static analyzer doesn't realize allocated `data` is saved to SDL_WINDOWTEXTUREDATA and not leaked here. */
         return -1;
     }
 
@@ -1184,6 +1185,7 @@ SDL_GetWindowDisplayMode(SDL_Window * window, SDL_DisplayMode * mode)
     } else if (!SDL_GetClosestDisplayModeForDisplay(SDL_GetDisplayForWindow(window),
                                              &fullscreen_mode,
                                              &fullscreen_mode)) {
+        SDL_zerop(mode);
         return SDL_SetError("Couldn't find display mode match");
     }