diff --git a/src/test/SDL_test_common.c b/src/test/SDL_test_common.c
index fbe1f18e67..2412ea14d4 100644
--- a/src/test/SDL_test_common.c
+++ b/src/test/SDL_test_common.c
@@ -840,7 +840,7 @@ static void SDLTest_PrintWindowFlag(char *text, size_t maxlen, SDL_WindowFlags f
         SDL_snprintfcat(text, maxlen, "TRANSPARENT");
         break;
     default:
-        SDL_snprintfcat(text, maxlen, "0x%8.8x", flag);
+        SDL_snprintfcat(text, maxlen, "0x%16.16" SDL_PRIx64, flag);
         break;
     }
 }
diff --git a/src/thread/windows/SDL_sysmutex.c b/src/thread/windows/SDL_sysmutex.c
index 6b1083ef4a..6ad755d7fa 100644
--- a/src/thread/windows/SDL_sysmutex.c
+++ b/src/thread/windows/SDL_sysmutex.c
@@ -146,7 +146,8 @@ static SDL_Mutex *SDL_CreateMutex_cs(void)
 #ifdef SDL_PLATFORM_WINRT
         InitializeCriticalSectionEx(&mutex->cs, 2000, 0);
 #else
-        InitializeCriticalSectionAndSpinCount(&mutex->cs, 2000);
+        // This function always succeeds
+        (void)InitializeCriticalSectionAndSpinCount(&mutex->cs, 2000);
 #endif
     }
     return (SDL_Mutex *)mutex;
diff --git a/src/video/SDL_blit_0.c b/src/video/SDL_blit_0.c
index ab06e41544..5ea34aeae4 100644
--- a/src/video/SDL_blit_0.c
+++ b/src/video/SDL_blit_0.c
@@ -928,10 +928,16 @@ SDL_BlitFunc SDL_CalculateBlit0(SDL_Surface *surface)
     if (SDL_PIXELTYPE(surface->format) == SDL_PIXELTYPE_INDEX1) {
         switch (surface->internal->map.info.flags & ~SDL_COPY_RLE_MASK) {
         case 0:
-            return bitmap_blit_1b[which];
+            if (which < SDL_arraysize(bitmap_blit_1b)) {
+                return bitmap_blit_1b[which];
+            }
+            break;
 
         case SDL_COPY_COLORKEY:
-            return colorkey_blit_1b[which];
+            if (which < SDL_arraysize(colorkey_blit_1b)) {
+                return colorkey_blit_1b[which];
+            }
+            break;
 
         case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
             return which >= 2 ? Blit1btoNAlpha : (SDL_BlitFunc)NULL;
@@ -945,10 +951,16 @@ SDL_BlitFunc SDL_CalculateBlit0(SDL_Surface *surface)
     if (SDL_PIXELTYPE(surface->format) == SDL_PIXELTYPE_INDEX2) {
         switch (surface->internal->map.info.flags & ~SDL_COPY_RLE_MASK) {
         case 0:
-            return bitmap_blit_2b[which];
+            if (which < SDL_arraysize(bitmap_blit_2b)) {
+                return bitmap_blit_2b[which];
+            }
+            break;
 
         case SDL_COPY_COLORKEY:
-            return colorkey_blit_2b[which];
+            if (which < SDL_arraysize(colorkey_blit_2b)) {
+                return colorkey_blit_2b[which];
+            }
+            break;
 
         case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
             return which >= 2 ? Blit2btoNAlpha : (SDL_BlitFunc)NULL;
@@ -962,10 +974,16 @@ SDL_BlitFunc SDL_CalculateBlit0(SDL_Surface *surface)
     if (SDL_PIXELTYPE(surface->format) == SDL_PIXELTYPE_INDEX4) {
         switch (surface->internal->map.info.flags & ~SDL_COPY_RLE_MASK) {
         case 0:
-            return bitmap_blit_4b[which];
+            if (which < SDL_arraysize(bitmap_blit_4b)) {
+                return bitmap_blit_4b[which];
+            }
+            break;
 
         case SDL_COPY_COLORKEY:
-            return colorkey_blit_4b[which];
+            if (which < SDL_arraysize(colorkey_blit_4b)) {
+                return colorkey_blit_4b[which];
+            }
+            break;
 
         case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
             return which >= 2 ? Blit4btoNAlpha : (SDL_BlitFunc)NULL;
diff --git a/src/video/SDL_blit_1.c b/src/video/SDL_blit_1.c
index 0c7cdc099a..2c8acbdb1f 100644
--- a/src/video/SDL_blit_1.c
+++ b/src/video/SDL_blit_1.c
@@ -526,10 +526,16 @@ SDL_BlitFunc SDL_CalculateBlit1(SDL_Surface *surface)
 
     switch (surface->internal->map.info.flags & ~SDL_COPY_RLE_MASK) {
     case 0:
-        return one_blit[which];
+        if (which < SDL_arraysize(one_blit)) {
+            return one_blit[which];
+        }
+        break;
 
     case SDL_COPY_COLORKEY:
-        return one_blitkey[which];
+        if (which < SDL_arraysize(one_blitkey)) {
+            return one_blitkey[which];
+        }
+        break;
 
     case SDL_COPY_COLORKEY | SDL_COPY_BLEND:  /* this is not super-robust but handles a specific case we found sdl12-compat. */
         return (surface->internal->map.info.a == 255) ? one_blitkey[which] :
diff --git a/test/checkkeys.c b/test/checkkeys.c
index 36aa88d439..3596605b64 100644
--- a/test/checkkeys.c
+++ b/test/checkkeys.c
@@ -561,10 +561,12 @@ int main(int argc, char *argv[])
 #endif
 
 done:
-    for (i = 0; i < state->num_windows; ++i) {
-        SDLTest_TextWindowDestroy(windowstates[i].textwindow);
+    if (windowstates) {
+        for (i = 0; i < state->num_windows; ++i) {
+            SDLTest_TextWindowDestroy(windowstates[i].textwindow);
+        }
+        SDL_free(windowstates);
     }
-    SDL_free(windowstates);
     SDLTest_CleanupTextDrawing();
     SDLTest_CommonQuit(state);
     return 0;
diff --git a/test/testautomation_stdlib.c b/test/testautomation_stdlib.c
index 701b8f6413..c489c58463 100644
--- a/test/testautomation_stdlib.c
+++ b/test/testautomation_stdlib.c
@@ -378,7 +378,7 @@ static int stdlib_swprintf(void *arg)
     const wchar_t *expected;
     size_t size;
 
-    result = SDL_swprintf(text, sizeof(text), L"%s", "foo");
+    result = SDL_swprintf(text, SDL_arraysize(text), L"%s", "foo");
     expected = L"foo";
     SDLTest_AssertPass("Call to SDL_swprintf(\"%%s\", \"foo\")");
     SDLTest_AssertCheck(SDL_wcscmp(text, expected) == 0, "Check text, expected: %S, got: %S", expected, text);