Fix T98904: GPencil sculpt brushes break after you delete a brush

There were two problems here:

1) Console warnings due to brush was None.
2) It was impossible to recreate a brush.

This patch fixes both issues and it is now possible to recreate any brush.

Differential Revision: https://developer.blender.org/D15213

Reviewed by: @dflelinto

2 files changed, 8 insertions, 5 deletions

diff --git a/release/scripts/startup/bl_ui/properties_paint_common.py b/release/scripts/startup/bl_ui/properties_paint_common.py
index 320b5f60911..e0c5da5ee1a 100644
--- a/release/scripts/startup/bl_ui/properties_paint_common.py
+++ b/release/scripts/startup/bl_ui/properties_paint_common.py
@@ -1295,6 +1295,8 @@ def brush_basic_gpencil_paint_settings(layout, context, brush, *, compact=False)
 
 
 def brush_basic_gpencil_sculpt_settings(layout, _context, brush, *, compact=False):
+    if brush is None:
+        return
     gp_settings = brush.gpencil_settings
     if gp_settings is None:
         return
diff --git a/release/scripts/startup/bl_ui/space_view3d.py b/release/scripts/startup/bl_ui/space_view3d.py
index a8624030564..625ba6016c6 100644
--- a/release/scripts/startup/bl_ui/space_view3d.py
+++ b/release/scripts/startup/bl_ui/space_view3d.py
@@ -97,7 +97,7 @@ class VIEW3D_HT_tool_header(Header):
         elif tool_mode == 'PAINT_GPENCIL':
             if is_valid_context:
                 brush = context.tool_settings.gpencil_paint.brush
-                if brush.gpencil_tool != 'ERASE':
+                if brush and brush.gpencil_tool != 'ERASE':
                     if brush.gpencil_tool != 'TINT':
                         layout.popover("VIEW3D_PT_tools_grease_pencil_brush_advanced")
 
@@ -108,10 +108,11 @@ class VIEW3D_HT_tool_header(Header):
         elif tool_mode == 'SCULPT_GPENCIL':
             if is_valid_context:
                 brush = context.tool_settings.gpencil_sculpt_paint.brush
-                tool = brush.gpencil_sculpt_tool
-                if tool in {'SMOOTH', 'RANDOMIZE'}:
-                    layout.popover("VIEW3D_PT_tools_grease_pencil_sculpt_options")
-                layout.popover("VIEW3D_PT_tools_grease_pencil_sculpt_appearance")
+                if brush:
+                    tool = brush.gpencil_sculpt_tool
+                    if tool in {'SMOOTH', 'RANDOMIZE'}:
+                        layout.popover("VIEW3D_PT_tools_grease_pencil_sculpt_options")
+                    layout.popover("VIEW3D_PT_tools_grease_pencil_sculpt_appearance")
         elif tool_mode == 'WEIGHT_GPENCIL':
             if is_valid_context:
                 layout.popover("VIEW3D_PT_tools_grease_pencil_weight_appearance")