commit a79925a0a8f00577782090859eb0ef69e220d4aa
author Bram Moolenaar <Bram@vim.org> Tue Jan 05 17:50:28 2021 +0100
committer Bram Moolenaar <Bram@vim.org> Tue Jan 05 17:50:28 2021 +0100
tree 2b6b2bb3a90f09a256d5b6dbdfefac238c015d65
parent 752fc692ace51459cb407ec117c147b3bbebc071

patch 8.2.2302: Vim9: using an option value may use uninitialized memory

Problem:    Vim9: using an option value may use uninitialized memory.
Solution:   Clear v_lock. (closes #7620)

src/testdir/test_vim9_expr.vim

diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 4941650..d835f04 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -2426,6 +2426,10 @@
   CheckScriptSuccess(lines)
 enddef
 
+def SetSomeVar()
+  b:someVar = &fdm
+enddef
+
 def Test_expr7_option()
   # option
   set ts=11
@@ -2443,6 +2447,11 @@
   var bval: bool = &tgc
   var nval: number = &ts
   var sval: string = &path
+
+  # check v_lock is cleared (requires using valgrind, doesn't always show)
+  SetSomeVar()
+  b:someVar = 0
+  unlet b:someVar
 enddef
 
 def Test_expr7_environment()

src/typval.c

diff --git a/src/typval.c b/src/typval.c
index 421e62a..d16f0e6 100644
--- a/src/typval.c
+++ b/src/typval.c
@@ -1117,6 +1117,7 @@
     }
     else if (rettv != NULL)
     {
+	rettv->v_lock = 0;
 	if (opt_type == gov_hidden_string)
 	{
 	    rettv->v_type = VAR_STRING;

src/version.c

diff --git a/src/version.c b/src/version.c
index c01221c..e7c3ee0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2302,
+/**/
     2301,
 /**/
     2300,