patch 9.0.1806: Vim9: bogus error on export

Problem:  Vim9: bogus error on export
Solution: Don't error out when the export command is not executed

closes: #12912
closes: #12930

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: LemonBoy <thatlemon@gmail.com>

src/ex_docmd.c

@@ -2586,8 +2586,8 @@ do_one_cmd(
 
 #ifdef FEAT_EVAL
     // A command will reset "is_export" when exporting an item.  If it is still
-    // set something went wrong.
-    if (is_export)
+    // set something went wrong or the command was never executed.
+    if (!ea.skip && is_export)
     {
 	if (errormsg == NULL)
 	    errormsg = _(e_export_with_invalid_argument);

src/testdir/test_vim9_import.vim

@@ -2919,5 +2919,15 @@ def Test_vim9_import_symlink()
   endif
 enddef
 
+def Test_export_in_conditional_block()
+  var lines =<< trim END
+      vim9script
+      if exists('this_will_fail')
+        export var MyVar = "hello"
+      endif
+  END
+  v9.CheckScriptSuccess(lines)
+enddef
+
 
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker

src/version.c

@@ -699,6 +699,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1806,
 /**/
     1805,
 /**/