patch 8.1.1345: stuck in sandbox with ":s/../\=Function/gn"

Problem:    Stuck in sandbox with ":s/../\=Function/gn".
Solution:   Don't skip over code to restore sandbox. (Christian Brabandt)

src/ex_cmds.c

@@ -5555,28 +5555,25 @@ do_sub(exarg_T *eap)
 #ifdef FEAT_EVAL
 		if (subflags.do_count)
 		{
-		    /* prevent accidentally changing the buffer by a function */
-		    save_ma = curbuf->b_p_ma;
+		    // prevent accidentally changing the buffer by a function
 		    curbuf->b_p_ma = FALSE;
 		    sandbox++;
 		}
-		/* Save flags for recursion.  They can change for e.g.
-		 * :s/^/\=execute("s#^##gn") */
+		// Save flags for recursion.  They can change for e.g.
+		// :s/^/\=execute("s#^##gn")
 		subflags_save = subflags;
+		save_ma = curbuf->b_p_ma;
 #endif
-		/* get length of substitution part */
+		// get length of substitution part
 		sublen = vim_regsub_multi(&regmatch,
 				    sub_firstlnum - regmatch.startpos[0].lnum,
 				    sub, sub_firstline, FALSE, p_magic, TRUE);
 #ifdef FEAT_EVAL
 		// If getting the substitute string caused an error, don't do
 		// the replacement.
-		if (aborting())
-		    goto skip;
-
 		// Don't keep flags set by a recursive call.
 		subflags = subflags_save;
-		if (subflags.do_count)
+		if (aborting() || subflags.do_count)
 		{
 		    curbuf->b_p_ma = save_ma;
 		    if (sandbox > 0)

src/testdir/test_substitute.vim

@@ -638,6 +638,17 @@ func Test_nocatch_sub_failure_handling()
   call assert_equal(1, error_caught)
   call assert_equal(['1 aaa', '2 aaa', '3 aaa'], getline(1, 3))
 
+  " Same, but using "n" flag so that "sandbox" gets set
+  call setline(1, ['1 aaa', '2 aaa', '3 aaa'])
+  let error_caught = 0
+  try
+    %s/aaa/\=Foo()/gn
+  catch
+    let error_caught = 1
+  endtry
+  call assert_equal(1, error_caught)
+  call assert_equal(['1 aaa', '2 aaa', '3 aaa'], getline(1, 3))
+
   bwipe!
 endfunc
 

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1345,
 /**/
     1344,
 /**/