From fd92647f3457bcd8d8c95d93f7e069c97a6599c4 Mon Sep 17 00:00:00 2001
From: Falk David <falk@blender.org>
Date: Tue, 12 Mar 2024 11:16:59 +0100
Subject: [PATCH] Fix: GPv3: Add missing check in `get_mutable_attribute`

The function didn't return early in case the domain was empty.
The fix makes sure we return an empty `MutableSpan` in this case
(add doesn't try to create a new custom data layer).
---
 source/blender/blenkernel/intern/grease_pencil.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/source/blender/blenkernel/intern/grease_pencil.cc b/source/blender/blenkernel/intern/grease_pencil.cc
index 684c98c835a..ea4a3f27961 100644
--- a/source/blender/blenkernel/intern/grease_pencil.cc
+++ b/source/blender/blenkernel/intern/grease_pencil.cc
@@ -266,6 +266,9 @@ static MutableSpan<T> get_mutable_attribute(CurvesGeometry &curves,
                                             const T default_value = T())
 {
   const int num = domain_num(curves, domain);
+  if (num == 0) {
+    return {};
+  }
   const eCustomDataType type = cpp_type_to_custom_data_type(CPPType::get<T>());
   CustomData &custom_data = domain_custom_data(curves, domain);