Fix for deleting the last uncommit character

src/video/cocoa/SDL_cocoakeyboard.m

@@ -144,6 +144,8 @@
 {
     [_markedText release];
     _markedText = nil;
+
+    SDL_SendEditingText("", 0, 0);
 }
 
 - (NSRect) firstRectForCharacterRange: (NSRange) theRange

test/testime.c

@@ -136,11 +136,13 @@ static void RenderText(SDL_Surface *sur,
                         int x, int y,
                         SDL_Color color)
 {
+    if (text && strlen(text)) {
         SDL_Surface *textSur = TTF_RenderUTF8_Blended(font, text, color);
         SDL_Rect dest = { x, y, textSur->w, textSur->h };
 
         SDL_BlitSurface(textSur, NULL, sur, &dest);
         SDL_FreeSurface(textSur);
+    }
 }
 #endif