Fix some overflows when exporting large files with blur effects

nyalldawson · nyalldawson · commit 7c97fdb32acb · 2023-03-03T16:20:56.000+10:00
diff --git a/src/core/effects/qgsimageoperation.cpp b/src/core/effects/qgsimageoperation.cpp
@@ -771,7 +771,7 @@ inline QRgb QgsImageOperation::GaussianBlurOperation::gaussianBlurVertical( cons
   for ( int i = 0; i <= mRadius * 2; ++i )
   {
     y = std::clamp( posy + ( i - mRadius ), 0, height - 1 );
-    ref = sourceFirstLine + sourceBpl * y;
+    ref = sourceFirstLine + static_cast< std::size_t >( sourceBpl ) * y;
 
     QRgb *refRgb = reinterpret_cast< QRgb * >( ref );
     r += mKernel[i] * qRed( *refRgb );
diff --git a/src/core/effects/qgsimageoperation.h b/src/core/effects/qgsimageoperation.h
@@ -445,7 +445,7 @@ class CORE_EXPORT QgsImageOperation
           int increment = ( mDirection == QgsImageOperation::ByRow ) ? 4 : bytesPerLine;
           if ( !mForwardDirection )
           {
-            p += ( lineLength - 1 ) * increment;
+            p += static_cast< std::size_t >( lineLength - 1 ) * increment;
             increment = -increment;
           }
 

Original file line number	Diff line number	Diff line change
`@@ -771,7 +771,7 @@ inline QRgb QgsImageOperation::GaussianBlurOperation::gaussianBlurVertical( cons`
`771`	`771`	`for ( int i = 0; i <= mRadius * 2; ++i )`
`772`	`772`	`{`
`773`	`773`	`y = std::clamp( posy + ( i - mRadius ), 0, height - 1 );`
`774`		`- ref = sourceFirstLine + sourceBpl * y;`
	`774`	`+ ref = sourceFirstLine + static_cast< std::size_t >( sourceBpl ) * y;`
`775`	`775`
`776`	`776`	`QRgb refRgb = reinterpret_cast< QRgb >( ref );`
`777`	`777`	`r += mKernel[i] * qRed( *refRgb );`
Original file line number	Diff line number	Diff line change
`@@ -445,7 +445,7 @@ class CORE_EXPORT QgsImageOperation`
`445`	`445`	`int increment = ( mDirection == QgsImageOperation::ByRow ) ? 4 : bytesPerLine;`
`446`	`446`	`if ( !mForwardDirection )`
`447`	`447`	`{`
`448`		`- p += ( lineLength - 1 ) * increment;`
	`448`	`+ p += static_cast< std::size_t >( lineLength - 1 ) * increment;`
`449`	`449`	`increment = -increment;`
`450`	`450`	`}`
`451`	`451`