To: vim_dev@googlegroups.com
Subject: Patch 8.1.0804
Fcc: outbox
From: Bram Moolenaar <Bram@moolenaar.net>
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------------

Patch 8.1.0804
Problem:    Crash when setting v:errmsg to empty list. (Jaon Franklin)
Solution:   Separate getting value and assigning result.
Files:	    src/eval.c, src/testdir/test_eval_stuff.vim


*** ../vim-8.1.0803/src/eval.c	2019-01-24 12:31:40.756926525 +0100
--- src/eval.c	2019-01-24 13:55:29.234651834 +0100
***************
*** 7892,7900 ****
  	{
  	    if (v->di_tv.v_type == VAR_STRING)
  	    {
! 		vim_free(v->di_tv.vval.v_string);
  		if (copy || tv->v_type != VAR_STRING)
! 		    v->di_tv.vval.v_string = vim_strsave(tv_get_string(tv));
  		else
  		{
  		    /* Take over the string to avoid an extra alloc/free. */
--- 7892,7907 ----
  	{
  	    if (v->di_tv.v_type == VAR_STRING)
  	    {
! 		VIM_CLEAR(v->di_tv.vval.v_string);
  		if (copy || tv->v_type != VAR_STRING)
! 		{
! 		    char_u *val = tv_get_string(tv);
! 
! 		    // Careful: when assigning to v:errmsg and tv_get_string()
! 		    // causes an error message the variable will alrady be set.
! 		    if (v->di_tv.vval.v_string == NULL)
! 			v->di_tv.vval.v_string = vim_strsave(val);
! 		}
  		else
  		{
  		    /* Take over the string to avoid an extra alloc/free. */
*** ../vim-8.1.0803/src/testdir/test_eval_stuff.vim	2019-01-13 19:10:28.963419901 +0100
--- src/testdir/test_eval_stuff.vim	2019-01-24 13:56:37.090182391 +0100
***************
*** 87,89 ****
--- 87,96 ----
    bwipe!
    call delete('XReadfile')
  endfunc
+ 
+ func Test_let_errmsg()
+   call assert_fails('let v:errmsg = []', 'E730:')
+   let v:errmsg = ''
+   call assert_fails('let v:errmsg = []', 'E730:')
+   let v:errmsg = ''
+ endfunc
*** ../vim-8.1.0803/src/version.c	2019-01-24 13:34:37.819464518 +0100
--- src/version.c	2019-01-24 13:47:30.569976005 +0100
***************
*** 793,794 ****
--- 793,796 ----
  {   /* Add new patch number below this line */
+ /**/
+     804,
  /**/

-- 
"My particular problem is with registry entries, which seem to just
accumulate like plastic coffee cups..."           -- Paul Moore

 /// Bram Moolenaar -- Bram@Moolenaar.net -- http://www.Moolenaar.net   \\\
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