fix(decor): enable decoration provider in on_start #33337

Problem:  An on_win-disabled decoration provider is left disabled for
          the on_buf callback during the next redraw (if the provider
          does not subscribe to on_end).

Solution: Move re-activation of the provider from after the on_end
          callback to before the on_start callback.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/nvim/decoration_provider.c b/src/nvim/decoration_provider.c
index 902e995ad5..fe92f820b4 100644
--- a/src/nvim/decoration_provider.c
+++ b/src/nvim/decoration_provider.c
@@ -118,6 +118,8 @@ void decor_providers_start(void)
       ADD_C(args, INTEGER_OBJ((int)display_tick));
       bool active = decor_provider_invoke((int)i, "start", p->redraw_start, args, true);
       kv_A(decor_providers, i).state = active ? kDecorProviderActive : kDecorProviderRedrawDisabled;
+    } else if (p->state != kDecorProviderDisabled) {
+      kv_A(decor_providers, i).state = kDecorProviderActive;
     }
   }
 }
@@ -220,7 +222,6 @@ void decor_providers_invoke_end(void)
       MAXSIZE_TEMP_ARRAY(args, 1);
       ADD_C(args, INTEGER_OBJ((int)display_tick));
       decor_provider_invoke((int)i, "end", p->redraw_end, args, true);
-      kv_A(decor_providers, i).state = kDecorProviderActive;
     }
   }
   decor_check_to_be_deleted();