patch 8.2.1282: Vim9: crash when using CheckScriptFailure()v8.2.1282

Problem:    Vim9: crash when using CheckScriptFailure() in
            Test_vim9script_call_fail_decl().
Solution:   Do not decrement the def_functions len unless the function was
            newly added.

3 files changed, 17 insertions, 8 deletions

diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index ed5972185..25c40c8b9 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -258,7 +258,7 @@ endfunc
 
 def Test_call_funcref()
   assert_equal(3, g:SomeFunc('abc'))
-  assert_fails('NotAFunc()', 'E117:')
+  assert_fails('NotAFunc()', 'E117:') # comment after call
   assert_fails('g:NotAFunc()', 'E117:')
 
   let lines =<< trim END
@@ -425,9 +425,7 @@ def Test_vim9script_call_fail_decl()
     enddef
     defcompile
   END
-  writefile(lines, 'Xcall_decl.vim')
-  assert_fails('source Xcall_decl.vim', 'E1054:')
-  delete('Xcall_decl.vim')
+  CheckScriptFailure(lines, 'E1054:')
 enddef
 
 def Test_vim9script_call_fail_type()
diff --git a/src/version.c b/src/version.c
index 4286eb0b3..4ef305162 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1282,
+/**/
     1281,
 /**/
     1280,
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 394433a12..0fe0b16dd 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -6945,6 +6945,7 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
     sctx_T	save_current_sctx = current_sctx;
     int		do_estack_push;
     int		emsg_before = called_emsg;
+    int		new_def_function = FALSE;
 
     // When using a function that was compiled before: Free old instructions.
     // Otherwise add a new entry in "def_functions".
@@ -6954,8 +6955,12 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 							 + ufunc->uf_dfunc_idx;
 	delete_def_function_contents(dfunc);
     }
-    else if (add_def_function(ufunc) == FAIL)
-	return FAIL;
+    else
+    {
+	if (add_def_function(ufunc) == FAIL)
+	    return FAIL;
+	new_def_function = TRUE;
+    }
 
     ufunc->uf_def_status = UF_COMPILING;
 
@@ -7439,10 +7444,14 @@ erret:
 	    delete_instr(((isn_T *)instr->ga_data) + idx);
 	ga_clear(instr);
 
-	// if using the last entry in the table we might as well remove it
-	if (!dfunc->df_deleted
+	// If using the last entry in the table and it was added above, we
+	// might as well remove it.
+	if (!dfunc->df_deleted && new_def_function
 			    && ufunc->uf_dfunc_idx == def_functions.ga_len - 1)
+	{
 	    --def_functions.ga_len;
+	    ufunc->uf_dfunc_idx = 0;
+	}
 	ufunc->uf_def_status = UF_NOT_COMPILED;
 
 	while (cctx.ctx_scope != NULL)