video/blit: fix -Wimplicit-fallthrough warnings

(cherry picked from commit f7961b7c9ad598b031cd033f19e93c6d882e8e41)

src/joystick/linux/SDL_sysjoystick.c

@@ -1487,6 +1487,7 @@ static void HandleInputEvents(SDL_Joystick *joystick)
                         HandleHat(joystick, hat_index, code % 2, events[i].value);
                         break;
                     }
+                    SDL_FALLTHROUGH;
                 default:
                     events[i].value = AxisCorrect(joystick, code, events[i].value);
                     SDL_PrivateJoystickAxis(joystick,
@@ -1569,6 +1570,7 @@ static void HandleClassicEvents(SDL_Joystick *joystick)
                         HandleHat(joystick, hat_index, code % 2, events[i].value);
                         break;
                     }
+                    SDL_FALLTHROUGH;
                 default:
                     SDL_PrivateJoystickAxis(joystick,
                                             joystick->hwdata->abs_map[code],

src/video/SDL_blit_1.c

@@ -140,6 +140,7 @@ static void Blit1to2(SDL_BlitInfo *info)
             case 3:
                 *(Uint16 *)dst = map[*src++];
                 dst += 2;
+                SDL_FALLTHROUGH;
             case 2:
                 *(Uint32 *)dst = (map[src[HI]] << 16) | (map[src[LO]]);
                 src += 2;
@@ -169,6 +170,7 @@ static void Blit1to2(SDL_BlitInfo *info)
             case 3:
                 *(Uint16 *)dst = map[*src++];
                 dst += 2;
+                SDL_FALLTHROUGH;
             case 2:
                 *(Uint32 *)dst = (map[src[HI]] << 16) | (map[src[LO]]);
                 src += 2;
@@ -270,8 +272,10 @@ static void Blit1to4(SDL_BlitInfo *info)
         switch (width & 3) {
         case 3:
             *dst++ = map[*src++];
+            SDL_FALLTHROUGH;
         case 2:
             *dst++ = map[*src++];
+            SDL_FALLTHROUGH;
         case 1:
             *dst++ = map[*src++];
         }

src/video/SDL_blit_N.c

@@ -999,9 +999,11 @@ static void Blit_RGB888_index8(SDL_BlitInfo *info)
             case 3:
                 RGB888_RGB332(*dst++, *src);
                 ++src;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB888_RGB332(*dst++, *src);
                 ++src;
+                SDL_FALLTHROUGH;
             case 1:
                 RGB888_RGB332(*dst++, *src);
                 ++src;
@@ -1043,10 +1045,12 @@ static void Blit_RGB888_index8(SDL_BlitInfo *info)
                 RGB888_RGB332(Pixel, *src);
                 *dst++ = map[Pixel];
                 ++src;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB888_RGB332(Pixel, *src);
                 *dst++ = map[Pixel];
                 ++src;
+                SDL_FALLTHROUGH;
             case 1:
                 RGB888_RGB332(Pixel, *src);
                 *dst++ = map[Pixel];
@@ -1109,9 +1113,11 @@ static void Blit_RGB101010_index8(SDL_BlitInfo *info)
             case 3:
                 RGB101010_RGB332(*dst++, *src);
                 ++src;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB101010_RGB332(*dst++, *src);
                 ++src;
+                SDL_FALLTHROUGH;
             case 1:
                 RGB101010_RGB332(*dst++, *src);
                 ++src;
@@ -1153,10 +1159,12 @@ static void Blit_RGB101010_index8(SDL_BlitInfo *info)
                 RGB101010_RGB332(Pixel, *src);
                 *dst++ = map[Pixel];
                 ++src;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB101010_RGB332(Pixel, *src);
                 *dst++ = map[Pixel];
                 ++src;
+                SDL_FALLTHROUGH;
             case 1:
                 RGB101010_RGB332(Pixel, *src);
                 *dst++ = map[Pixel];
@@ -1248,6 +1256,7 @@ static void Blit_RGB888_RGB555(SDL_BlitInfo *info)
                 RGB888_RGB555(dst, src);
                 ++src;
                 ++dst;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB888_RGB555_TWO(dst, src);
                 src += 2;
@@ -1279,6 +1288,7 @@ static void Blit_RGB888_RGB555(SDL_BlitInfo *info)
                 RGB888_RGB555(dst, src);
                 ++src;
                 ++dst;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB888_RGB555_TWO(dst, src);
                 src += 2;
@@ -1376,6 +1386,7 @@ static void Blit_RGB888_RGB565(SDL_BlitInfo *info)
                 RGB888_RGB565(dst, src);
                 ++src;
                 ++dst;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB888_RGB565_TWO(dst, src);
                 src += 2;
@@ -1407,6 +1418,7 @@ static void Blit_RGB888_RGB565(SDL_BlitInfo *info)
                 RGB888_RGB565(dst, src);
                 ++src;
                 ++dst;
+                SDL_FALLTHROUGH;
             case 2:
                 RGB888_RGB565_TWO(dst, src);
                 src += 2;
@@ -1478,9 +1490,11 @@ static void Blit_RGB565_32(SDL_BlitInfo *info, const Uint32 *map)
         case 3:
             *dst++ = RGB565_32(dst, src, map);
             src += 2;
+            SDL_FALLTHROUGH;
         case 2:
             *dst++ = RGB565_32(dst, src, map);
             src += 2;
+            SDL_FALLTHROUGH;
         case 1:
             *dst++ = RGB565_32(dst, src, map);
             src += 2;