Fix bug 1789: SDL_IntersectRect intersection with empty rect does not set result to empty; add test coverage to Rect suite

src/video/SDL_rect.c

@@ -29,8 +29,13 @@ SDL_HasIntersection(const SDL_Rect * A, const SDL_Rect * B)
 {
     int Amin, Amax, Bmin, Bmax;
 
-    if (!A || !B) {
+    if (!A) {
-        // TODO error message
+        SDL_InvalidParamError("A");
+        return SDL_FALSE;
+    }
+
+    if (!B) {
+        SDL_InvalidParamError("B");
         return SDL_FALSE;
     }
 
@@ -71,13 +76,25 @@ SDL_IntersectRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result)
 {
     int Amin, Amax, Bmin, Bmax;
 
-    if (!A || !B || !result) {
+    if (!A) {
-        // TODO error message
+        SDL_InvalidParamError("A");
+        return SDL_FALSE;
+    }
+
+    if (!B) {
+        SDL_InvalidParamError("B");
+        return SDL_FALSE;
+    }
+    
+    if (!result) {
+        SDL_InvalidParamError("result");
         return SDL_FALSE;
     }
 
     /* Special cases for empty rects */
     if (SDL_RectEmpty(A) || SDL_RectEmpty(B)) {
+        result->w = 0;
+        result->h = 0;
         return SDL_FALSE;
     }
     
@@ -113,7 +130,18 @@ SDL_UnionRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result)
 {
     int Amin, Amax, Bmin, Bmax;
 
-    if (!A || !B || !result) {
+    if (!A) {
+        SDL_InvalidParamError("A");
+        return;
+    }
+
+    if (!B) {
+        SDL_InvalidParamError("B");
+        return;
+    }
+    
+    if (!result) {
+        SDL_InvalidParamError("result");
         return;
     }
 
@@ -171,12 +199,12 @@ SDL_EnclosePoints(const SDL_Point * points, int count, const SDL_Rect * clip,
     int x, y, i;
 
     if (!points) {
-        /* TODO error message */
+        SDL_InvalidParamError("points");
         return SDL_FALSE;
     }
 
     if (count < 1) {
-        /* TODO error message */
+        SDL_InvalidParamError("count");
         return SDL_FALSE;
     }
 
@@ -298,8 +326,28 @@ SDL_IntersectRectAndLine(const SDL_Rect * rect, int *X1, int *Y1, int *X2,
     int recty2;
     int outcode1, outcode2;
 
-    if (!rect || !X1 || !Y1 || !X2 || !Y2) {
+    if (!rect) {
-        // TODO error message
+        SDL_InvalidParamError("rect");
+        return SDL_FALSE;
+    }
+    
+    if (!X1) {
+        SDL_InvalidParamError("X1");
+        return SDL_FALSE;
+    }
+    
+    if (!Y1) {
+        SDL_InvalidParamError("Y1");
+        return SDL_FALSE;
+    }
+    
+    if (!X2) {
+        SDL_InvalidParamError("X2");
+        return SDL_FALSE;
+    }
+    
+    if (!Y2) {
+        SDL_InvalidParamError("Y2");
         return SDL_FALSE;
     }
 
@@ -418,18 +466,28 @@ SDL_GetSpanEnclosingRect(int width, int height,
     int span_y1, span_y2;
     int rect_y1, rect_y2;
 
-    if (width < 1 || height < 1) {
+    if (width < 1) {
-        // TODO error message
+        SDL_InvalidParamError("width");
         return SDL_FALSE;
     }
 
-    if (!rects || !span) {
+    if (height < 1) {
-        // TODO error message
+        SDL_InvalidParamError("height");
+        return SDL_FALSE;
+    }
+
+    if (!rects) {
+        SDL_InvalidParamError("rects");
+        return SDL_FALSE;
+    }
+
+    if (!span) {
+        SDL_InvalidParamError("span");
         return SDL_FALSE;
     }
 
     if (numrects < 1) {
-        // TODO error message
+        SDL_InvalidParamError("numrects");
         return SDL_FALSE;
     }
 

test/testautomation_rect.c

@@ -614,8 +614,11 @@ int rect_testIntersectRectEmpty (void *arg)
     SDL_Rect rectB;
     SDL_Rect result;
     SDL_bool intersection;
+    SDL_bool empty;
 
     // Rect A empty
+    result.w = SDLTest_RandomIntegerInRange(1, 100);
+    result.h = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.x = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.y = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.w = SDLTest_RandomIntegerInRange(1, 100);
@@ -627,8 +630,12 @@ int rect_testIntersectRectEmpty (void *arg)
     rectB = refRectB;
     intersection = SDL_IntersectRect(&rectA, &rectB, &result);
     _validateIntersectRectResults(intersection, SDL_FALSE, &rectA, &rectB, &refRectA, &refRectB, (SDL_Rect *)NULL, (SDL_Rect *)NULL);
+    empty = (SDL_bool)SDL_RectEmpty(&result);
+    SDLTest_AssertCheck(empty == SDL_TRUE, "Validate result is empty Rect; got: %s", (empty == SDL_TRUE) ? "SDL_TRUE" : "SDL_FALSE");
     
     // Rect B empty
+    result.w = SDLTest_RandomIntegerInRange(1, 100);
+    result.h = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.x = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.y = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.w = SDLTest_RandomIntegerInRange(1, 100);
@@ -640,8 +647,12 @@ int rect_testIntersectRectEmpty (void *arg)
     rectB = refRectB;
     intersection = SDL_IntersectRect(&rectA, &rectB, &result);
     _validateIntersectRectResults(intersection, SDL_FALSE, &rectA, &rectB, &refRectA, &refRectB, (SDL_Rect *)NULL, (SDL_Rect *)NULL);
+    empty = (SDL_bool)SDL_RectEmpty(&result);
+    SDLTest_AssertCheck(empty == SDL_TRUE, "Validate result is empty Rect; got: %s", (empty == SDL_TRUE) ? "SDL_TRUE" : "SDL_FALSE");
 
     // Rect A and B empty
+    result.w = SDLTest_RandomIntegerInRange(1, 100);
+    result.h = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.x = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.y = SDLTest_RandomIntegerInRange(1, 100);
     refRectA.w = SDLTest_RandomIntegerInRange(1, 100);
@@ -655,6 +666,8 @@ int rect_testIntersectRectEmpty (void *arg)
     rectB = refRectB;
     intersection = SDL_IntersectRect(&rectA, &rectB, &result);
     _validateIntersectRectResults(intersection, SDL_FALSE, &rectA, &rectB, &refRectA, &refRectB, (SDL_Rect *)NULL, (SDL_Rect *)NULL);
+    empty = (SDL_bool)SDL_RectEmpty(&result);
+    SDLTest_AssertCheck(empty == SDL_TRUE, "Validate result is empty Rect; got: %s", (empty == SDL_TRUE) ? "SDL_TRUE" : "SDL_FALSE");
 
     return TEST_COMPLETED;
 }