Bugfix #25657

Three code fixes for 1 report. User experienced crashes while
painting on float buffer + having preview renders on.

- Texture Nodes: Image was re-allocated without using
  proper thread lock
- Paint code: old convention to free the byte rect from
  a float image as signal to re-create now is a proper
  flag. This keeps image memory unchanged. Nice for render.
- Imbuf: call to make a byte rect from float was freeing
  mipmaps unnecessary.

1 files changed, 7 insertions, 1 deletions

diff --git a/source/blender/nodes/intern/TEX_nodes/TEX_image.c b/source/blender/nodes/intern/TEX_nodes/TEX_image.c
index c764c7a22d2..7c680b4c25a 100644
--- a/source/blender/nodes/intern/TEX_nodes/TEX_image.c
+++ b/source/blender/nodes/intern/TEX_nodes/TEX_image.c
@@ -58,7 +58,13 @@ static void colorfn(float *out, TexParams *p, bNode *node, bNodeStack **UNUSED(i
 			py = (int)( (y-yoff) * ysize );
 		
 			if( (!xsize) || (!ysize) ) return;
-			if( !ibuf->rect_float ) IMB_float_from_rect(ibuf);
+			
+			if( !ibuf->rect_float ) {
+				BLI_lock_thread(LOCK_IMAGE);
+				if( !ibuf->rect_float )
+					IMB_float_from_rect(ibuf);
+				BLI_unlock_thread(LOCK_IMAGE);
+			}
 			
 			while( px < 0 ) px += ibuf->x;
 			while( py < 0 ) py += ibuf->y;