commit 08f7a41b0a280e5901eb4ee4bbfe682113863492
author Bram Moolenaar <Bram@vim.org> Mon Jul 13 20:41:08 2020 +0200
committer Bram Moolenaar <Bram@vim.org> Mon Jul 13 20:41:08 2020 +0200
tree c5a4c229cde639d8c6518e3dcb79f014ddca90ab
parent f1a2368d81fc3f70dfcf7d577957185da6ccf0b6

patch 8.2.1202: Vim9: crash when calling a closure from a builtin function

Problem:    Vim9: crash when calling a closure from a builtin function.
Solution:   Use the current execution context. (closes #6441)

src/vim9execute.c

diff --git a/src/vim9execute.c b/src/vim9execute.c
index 5fdbfbf..eb900c8 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -461,6 +461,10 @@
     return OK;
 }
 
+// Ugly global to avoid passing the execution context around through many
+// layers.
+static ectx_T *current_ectx = NULL;
+
 /*
  * Call a builtin function by index.
  */
@@ -470,12 +474,16 @@
     typval_T	argvars[MAX_FUNC_ARGS];
     int		idx;
     int		did_emsg_before = did_emsg;
+    ectx_T	*prev_ectx = current_ectx;
 
     if (call_prepare(argcount, argvars, ectx) == FAIL)
 	return FAIL;
 
-    // Call the builtin function.
+    // Call the builtin function.  Set "current_ectx" so that when it
+    // recursively invokes call_def_function() a closure context can be set.
+    current_ectx = ectx;
     call_internal_func_by_idx(func_idx, argvars, STACK_TV_BOT(-1));
+    current_ectx = prev_ectx;
 
     // Clear the arguments.
     for (idx = 0; idx < argcount; ++idx)
@@ -749,8 +757,17 @@
 
     if (partial != NULL)
     {
-	ectx.ec_outer_stack = partial->pt_ectx_stack;
-	ectx.ec_outer_frame = partial->pt_ectx_frame;
+	if (partial->pt_ectx_stack == NULL && current_ectx != NULL)
+	{
+	    // TODO: is this always the right way?
+	    ectx.ec_outer_stack = &current_ectx->ec_stack;
+	    ectx.ec_outer_frame = current_ectx->ec_frame_idx;
+	}
+	else
+	{
+	    ectx.ec_outer_stack = partial->pt_ectx_stack;
+	    ectx.ec_outer_frame = partial->pt_ectx_frame;
+	}
     }
 
     // dummy frame entries