Bugfix #22040

Old bug report:

Image Editor, Painting: crash when texture was visible in 
Material or Texture preview. Was caused by paint code
freeing mipmaps. Now replaced with a mipmap tag (to be done
again), and a new mipmap function that doesn't re-allocate.

1 files changed, 20 insertions, 13 deletions

diff --git a/source/blender/imbuf/intern/scaling.c b/source/blender/imbuf/intern/scaling.c
index 73dcc0c8ea9..1f50deaee2a 100644
--- a/source/blender/imbuf/intern/scaling.c
+++ b/source/blender/imbuf/intern/scaling.c
@@ -286,26 +286,16 @@ struct ImBuf *IMB_double_y(struct ImBuf *ibuf1)
 	return (ibuf2);
 }
 
-
-struct ImBuf *IMB_onehalf(struct ImBuf *ibuf1)
+/* result in ibuf2, scaling should be done correctly */
+void imb_onehalf_no_alloc(struct ImBuf *ibuf2, struct ImBuf *ibuf1)
 {
-	struct ImBuf *ibuf2;
 	uchar *p1, *p2 = NULL, *dest;
 	float *p1f, *destf, *p2f = NULL;
 	int x,y;
 	int do_rect, do_float;
 
-	if (ibuf1==NULL) return (0);
-	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);
-
 	do_rect= (ibuf1->rect != NULL);
-
-	if (ibuf1->x <= 1) return(IMB_half_y(ibuf1));
-	if (ibuf1->y <= 1) return(IMB_half_x(ibuf1));
 	
-	ibuf2=IMB_allocImBuf((ibuf1->x)/2, (ibuf1->y)/2, ibuf1->depth, ibuf1->flags);
-	if (ibuf2==NULL) return (0);
-
 	p1f = ibuf1->rect_float;
 	destf=ibuf2->rect_float;
 	p1 = (uchar *) ibuf1->rect;
@@ -343,9 +333,26 @@ struct ImBuf *IMB_onehalf(struct ImBuf *ibuf1)
 			if (do_float) p1f+=4;
 		}
 	}
-	return (ibuf2);
+	
 }
 
+struct ImBuf *IMB_onehalf(struct ImBuf *ibuf1)
+{
+	struct ImBuf *ibuf2;
+
+	if (ibuf1==NULL) return (0);
+	if (ibuf1->rect==NULL && ibuf1->rect_float==NULL) return (0);
+	
+	if (ibuf1->x <= 1) return(IMB_half_y(ibuf1));
+	if (ibuf1->y <= 1) return(IMB_half_x(ibuf1));
+	
+	ibuf2=IMB_allocImBuf((ibuf1->x)/2, (ibuf1->y)/2, ibuf1->depth, ibuf1->flags);
+	if (ibuf2==NULL) return (0);
+	
+	imb_onehalf_no_alloc(ibuf2, ibuf1);
+	
+	return (ibuf2);
+}
 
 /* q_scale_linear_interpolation helper functions */