Ensure large offsets do not result in SEGV

kleisauke · kleisauke · commit b90542ed6641 · 2020-05-26T11:01:39.000+02:00
[skip ci]
diff --git a/libvips/resample/reduceh.cpp b/libvips/resample/reduceh.cpp
@@ -309,7 +309,8 @@ vips_reduceh_gen( VipsRegion *out_region, void *seq,
 
 	s.left = r->left * reduceh->hshrink;
 	s.top = r->top;
-	s.width = r->width * reduceh->hshrink + reduceh->n_point;
+	s.width = r->width * reduceh->hshrink + reduceh->n_point
+		+ reduceh->hoffset;
 	s.height = r->height;
 	if( vips_region_prepare( ir, &s ) )
 		return( -1 );
@@ -494,7 +495,7 @@ vips_reduceh_build( VipsObject *object )
 	 */
 	if( vips_embed( in, &t[1], 
 		left, 0, 
-		in->Xsize + reduceh->n_point - 1, in->Ysize,
+		in->Xsize + reduceh->n_point + reduceh->hoffset, in->Ysize,
 		"extend", VIPS_EXTEND_COPY,
 		(void *) NULL ) )
 		return( -1 );
diff --git a/libvips/resample/reducev.cpp b/libvips/resample/reducev.cpp
@@ -536,7 +536,8 @@ vips_reducev_gen( VipsRegion *out_region, void *vseq,
 	s.left = r->left;
 	s.top = r->top * reducev->vshrink;
 	s.width = r->width;
-	s.height = r->height * reducev->vshrink + reducev->n_point;
+	s.height = r->height * reducev->vshrink + reducev->n_point
+		+ reducev->voffset;
 	if( vips_region_prepare( ir, &s ) )
 		return( -1 );
 
@@ -650,7 +651,8 @@ vips_reducev_vector_gen( VipsRegion *out_region, void *vseq,
 	s.left = r->left;
 	s.top = r->top * reducev->vshrink;
 	s.width = r->width;
-	s.height = r->height * reducev->vshrink + reducev->n_point;
+	s.height = r->height * reducev->vshrink + reducev->n_point
+		+ reducev->voffset;
 	if( vips_region_prepare( ir, &s ) )
 		return( -1 );
 
@@ -873,7 +875,7 @@ vips_reducev_build( VipsObject *object )
 	 */
 	if( vips_embed( in, &t[1], 
 		0, top, 
-		in->Xsize, in->Ysize + reducev->n_point - 1, 
+		in->Xsize, in->Ysize + reducev->n_point + reducev->voffset, 
 		"extend", VIPS_EXTEND_COPY,
 		(void *) NULL ) )
 		return( -1 );
