ImDrawList::ChannelsSplit(), ImDrawListSlitter: Fixed an issue with merging draw commands between channels 0 and 1. (#2624) Introduced by cef88f6aae.

docs/CHANGELOG.txt

@@ -41,6 +41,9 @@ Breaking Changes:
   If you were still using the old names, read "API Breaking Changes" section of imgui.cpp to find out
   the new names and equivalent.
 
+Other Changes:
+- ImDrawList::ChannelsSplit(), ImDrawListSlitter: Fixed an issue with merging draw commands between channel 0 and 1. (#2624)
+
 
 -----------------------------------------------------------------------
  VERSION 1.71 (Released 2019-06-12)

imgui_draw.cpp

@@ -1262,7 +1262,7 @@ void ImDrawListSplitter::Merge(ImDrawList* draw_list)
     // Calculate our final buffer sizes. Also fix the incorrect IdxOffset values in each command.
     int new_cmd_buffer_count = 0;
     int new_idx_buffer_count = 0;
-    ImDrawCmd* last_cmd = (_Count > 0 && _Channels[0]._CmdBuffer.Size > 0) ? &_Channels[0]._CmdBuffer.back() : NULL;
+    ImDrawCmd* last_cmd = (_Count > 0 && draw_list->CmdBuffer.Size > 0) ? &draw_list->CmdBuffer.back() : NULL;
     int idx_offset = last_cmd ? last_cmd->IdxOffset + last_cmd->ElemCount : 0;
     for (int i = 1; i < _Count; i++)
     {