fixed teco_doc_undo_exchange(): use reference counting now

* When popping from the Q-Register stack to local Q-Registers in macro calls,
  problems would arise when rubbing out that macro call since we would eventually restore
  a pointer that has been permanently freed along with the local Q-Registers.
* Naturally this could result in everything from Valgrind warnings to crashes.
* Added test case.
* There is still a test case that fails when run under `--valgrind`,
  but it's apparently due to a glib-internal memory leak.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/doc.h b/src/doc.h
index 4ecfd21..99568ff 100644
--- a/src/doc.h
+++ b/src/doc.h
@@ -33,6 +33,8 @@
  */
 typedef struct teco_doc_scintilla_t teco_doc_scintilla_t;
 
+TECO_DECLARE_UNDO_OBJECT(doc_scintilla, teco_doc_scintilla_t *);
+
 /**
  * A Scintilla document.
  *
@@ -108,7 +110,7 @@ void teco_doc_exchange(teco_doc_t *ctx, teco_doc_t *other);
 static inline void
 teco_doc_undo_exchange(teco_doc_t *ctx)
 {
-	teco_undo_ptr(ctx->doc);
+	teco_undo_object_doc_scintilla_push(&ctx->doc);
 	teco_doc_undo_reset(ctx);
 }