patch 8.0.1817: a timer may change v:count unexpectedlyv8.0.1817

Problem:    A timer may change v:count unexpectedly.
Solution:   Save and restore v:count and similar variables when a timer
            callback is invoked. (closes #2897)

1 files changed, 23 insertions, 0 deletions

diff --git a/src/eval.c b/src/eval.c
index 63f8bde329..b787474d10 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -6462,6 +6462,29 @@ set_vcount(
 }
 
 /*
+ * Save variables that might be changed as a side effect.  Used when executing
+ * a timer callback.
+ */
+    void
+save_vimvars(vimvars_save_T *vvsave)
+{
+    vvsave->vv_prevcount = vimvars[VV_PREVCOUNT].vv_nr;
+    vvsave->vv_count = vimvars[VV_COUNT].vv_nr;
+    vvsave->vv_count1 = vimvars[VV_COUNT1].vv_nr;
+}
+
+/*
+ * Restore variables saved by save_vimvars().
+ */
+    void
+restore_vimvars(vimvars_save_T *vvsave)
+{
+    vimvars[VV_PREVCOUNT].vv_nr = vvsave->vv_prevcount;
+    vimvars[VV_COUNT].vv_nr = vvsave->vv_count;
+    vimvars[VV_COUNT1].vv_nr = vvsave->vv_count1;
+}
+
+/*
  * Set string v: variable to a copy of "val".
  */
     void