[Bf-blender-cvs] [ada60125188] master: Fix T99854: Crash converting legacy NURBS curves to new type

[Hans Goudey]

Commit: ada601251889c2344a4a89c269cc85877eeb9ebc
Author: Hans Goudey
Date:   Thu Jul 21 12:13:25 2022 -0500
Branches: master
https://developer.blender.org/rBada601251889c2344a4a89c269cc85877eeb9ebc

Fix T99854: Crash converting legacy NURBS curves to new type

Creating the attributes was done inside a parallel loop. Also correct a
typo for the parallel grain size, which was meant to be a power of two.

===================================================================

M	source/blender/blenkernel/intern/curve_legacy_convert.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/curve_legacy_convert.cc b/source/blender/blenkernel/intern/curve_legacy_convert.cc
index ff5bbc32afe..5c62f292832 100644
--- a/source/blender/blenkernel/intern/curve_legacy_convert.cc
+++ b/source/blender/blenkernel/intern/curve_legacy_convert.cc
@@ -115,7 +115,7 @@ Curves *curve_legacy_to_curves(const Curve &curve_legacy, const ListBase &nurbs_
   MutableSpan<float> tilts = curves.tilt_for_write();
 
   auto create_poly = [&](IndexMask selection) {
-    threading::parallel_for(selection.index_range(), 246, [&](IndexRange range) {
+    threading::parallel_for(selection.index_range(), 256, [&](IndexRange range) {
       for (const int curve_i : selection.slice(range)) {
         const Nurb &src_curve = *src_curves[curve_i];
         const Span<BPoint> src_points(src_curve.bp, src_curve.pntsu);
@@ -142,7 +142,7 @@ Curves *curve_legacy_to_curves(const Curve &curve_legacy, const ListBase &nurbs_
     MutableSpan<int8_t> handle_types_l = curves.handle_types_left_for_write();
     MutableSpan<int8_t> handle_types_r = curves.handle_types_right_for_write();
 
-    threading::parallel_for(selection.index_range(), 246, [&](IndexRange range) {
+    threading::parallel_for(selection.index_range(), 256, [&](IndexRange range) {
       for (const int curve_i : selection.slice(range)) {
         const Nurb &src_curve = *src_curves[curve_i];
         const Span<BezTriple> src_points(src_curve.bezt, src_curve.pntsu);
@@ -165,12 +165,12 @@ Curves *curve_legacy_to_curves(const Curve &curve_legacy, const ListBase &nurbs_
   };
 
   auto create_nurbs = [&](IndexMask selection) {
-    threading::parallel_for(selection.index_range(), 246, [&](IndexRange range) {
-      MutableSpan<int> resolutions = curves.resolution_for_write();
-      MutableSpan<float> nurbs_weights = curves.nurbs_weights_for_write();
-      MutableSpan<int8_t> nurbs_orders = curves.nurbs_orders_for_write();
-      MutableSpan<int8_t> nurbs_knots_modes = curves.nurbs_knots_modes_for_write();
-
+    MutableSpan<int> resolutions = curves.resolution_for_write();
+    MutableSpan<float> nurbs_weights = curves.nurbs_weights_for_write();
+    MutableSpan<int8_t> nurbs_orders = curves.nurbs_orders_for_write();
+    MutableSpan<int8_t> nurbs_knots_modes = curves.nurbs_knots_modes_for_write();
+    
+    threading::parallel_for(selection.index_range(), 256, [&](IndexRange range) {
       for (const int curve_i : selection.slice(range)) {
         const Nurb &src_curve = *src_curves[curve_i];
         const Span src_points(src_curve.bp, src_curve.pntsu);