To: vim_dev@googlegroups.com
Subject: Patch 9.0.1501
Fcc: outbox
From: Bram Moolenaar <Bram@moolenaar.net>
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------------

Patch 9.0.1501
Problem:    Crash with nested :try and :throw in catch block.
Solution:   Jump to :endtry before returning from function. (closes #12245)
Files:      src/vim9execute.c, src/testdir/test_vim9_script.vim


*** ../vim-9.0.1500/src/vim9execute.c	2023-04-18 21:04:49.431579535 +0100
--- src/vim9execute.c	2023-04-30 18:48:57.563368716 +0100
***************
*** 3053,3058 ****
--- 3053,3068 ----
  		goto theend;
  	    did_throw = TRUE;
  	    *msg_list = NULL;
+ 
+ 	    // This exception was not caught (yet).
+ 	    garray_T	*trystack = &ectx->ec_trystack;
+ 	    if (trystack->ga_len > 0)
+ 	    {
+ 		trycmd_T *trycmd = ((trycmd_T *)trystack->ga_data)
+ 							+ trystack->ga_len - 1;
+ 		if (trycmd->tcd_frame_idx == ectx->ec_frame_idx)
+ 		    trycmd->tcd_caught = FALSE;
+ 	    }
  	}
  
  	if (unlikely(did_throw))
***************
*** 3066,3072 ****
  	    while (index > 0)
  	    {
  		trycmd = ((trycmd_T *)trystack->ga_data) + index - 1;
! 		if (!trycmd->tcd_in_catch || trycmd->tcd_finally_idx != 0)
  		    break;
  		// In the catch and finally block of this try we have to go up
  		// one level.
--- 3076,3086 ----
  	    while (index > 0)
  	    {
  		trycmd = ((trycmd_T *)trystack->ga_data) + index - 1;
! 		// 1. after :try and before :catch - jump to first :catch
! 		// 2. in :catch block - jump to :finally
! 		// 3. in :catch block and no finally - jump to :endtry
! 		if (!trycmd->tcd_in_catch || trycmd->tcd_finally_idx != 0
! 				|| trycmd->tcd_frame_idx == ectx->ec_frame_idx)
  		    break;
  		// In the catch and finally block of this try we have to go up
  		// one level.
***************
*** 3077,3096 ****
  	    {
  		if (trycmd->tcd_in_catch)
  		{
! 		    // exception inside ":catch", jump to ":finally" once
! 		    ectx->ec_iidx = trycmd->tcd_finally_idx;
! 		    trycmd->tcd_finally_idx = 0;
  		}
  		else
  		    // jump to first ":catch"
  		    ectx->ec_iidx = trycmd->tcd_catch_idx;
! 		trycmd->tcd_in_catch = TRUE;
  		did_throw = FALSE;  // don't come back here until :endtry
  		trycmd->tcd_did_throw = TRUE;
  	    }
  	    else
  	    {
! 		// Not inside try or need to return from current functions.
  		// Push a dummy return value.
  		if (GA_GROW_FAILS(&ectx->ec_stack, 1))
  		    goto theend;
--- 3091,3121 ----
  	    {
  		if (trycmd->tcd_in_catch)
  		{
! 		    if (trycmd->tcd_finally_idx > 0)
! 		    {
! 			// exception inside ":catch", jump to ":finally" once
! 			ectx->ec_iidx = trycmd->tcd_finally_idx;
! 			trycmd->tcd_finally_idx = 0;
! 		    }
! 		    else
! 		    {
! 			// exception inside ":catch" or ":finally", jump to
! 			// ":endtry"
! 			ectx->ec_iidx = trycmd->tcd_endtry_idx;
! 		    }
  		}
  		else
+ 		{
  		    // jump to first ":catch"
  		    ectx->ec_iidx = trycmd->tcd_catch_idx;
! 		    trycmd->tcd_in_catch = TRUE;
! 		}
  		did_throw = FALSE;  // don't come back here until :endtry
  		trycmd->tcd_did_throw = TRUE;
  	    }
  	    else
  	    {
! 		// Not inside try or need to return from current function.
  		// Push a dummy return value.
  		if (GA_GROW_FAILS(&ectx->ec_stack, 1))
  		    goto theend;
***************
*** 4652,4658 ****
  
  		    if (trystack->ga_len == 0 && trylevel == 0 && emsg_silent)
  		    {
! 			// throwing an exception while using "silent!" causes
  			// the function to abort but not display an error.
  			tv = STACK_TV_BOT(-1);
  			clear_tv(tv);
--- 4677,4683 ----
  
  		    if (trystack->ga_len == 0 && trylevel == 0 && emsg_silent)
  		    {
! 			// Throwing an exception while using "silent!" causes
  			// the function to abort but not display an error.
  			tv = STACK_TV_BOT(-1);
  			clear_tv(tv);
*** ../vim-9.0.1500/src/testdir/test_vim9_script.vim	2023-01-28 19:38:45.785687265 +0000
--- src/testdir/test_vim9_script.vim	2023-04-30 17:45:59.927234001 +0100
***************
*** 812,817 ****
--- 812,852 ----
    v9.CheckDefAndScriptSuccess(lines)
  enddef
  
+ def Test_throw_in_nested_try()
+   var lines =<< trim END
+       vim9script
+ 
+       def Try(F: func(): void)
+         try
+           F()
+         catch
+         endtry
+       enddef
+ 
+       class X
+         def F()
+           try
+             throw 'Foobar'
+           catch
+             throw v:exception
+           endtry
+         enddef
+       endclass
+ 
+       def Test_TryMethod()
+         var x = X.new()
+         Try(() => x.F())
+       enddef
+ 
+ 
+       try
+         Test_TryMethod()
+       catch
+       endtry
+   END
+   v9.CheckScriptSuccess(lines)
+ enddef
+ 
  def Test_try_var_decl()
    var lines =<< trim END
        vim9script
*** ../vim-9.0.1500/src/version.c	2023-04-30 15:29:52.553140524 +0100
--- src/version.c	2023-04-30 17:46:07.243234583 +0100
***************
*** 697,698 ****
--- 697,700 ----
  {   /* Add new patch number below this line */
+ /**/
+     1501,
  /**/

-- 
            |

Ceci n'est pas une pipe.

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