patch 8.1.1061: when substitute string throws error, substitute happens anyway

Problem:    When substitute string throws error, substitute happens anyway.
Solution:   Skip substitution when aborting. (closes #4161)
diff --git a/src/testdir/test_substitute.vim b/src/testdir/test_substitute.vim
index f01e60e..790f238 100644
--- a/src/testdir/test_substitute.vim
+++ b/src/testdir/test_substitute.vim
@@ -610,3 +610,33 @@
   enew!
   set titlestring&
 endfunc
+
+func Test_nocatch_sub_failure_handling()
+  " normal error results in all replacements 
+  func! Foo()
+    foobar
+  endfunc
+  new
+  call setline(1, ['1 aaa', '2 aaa', '3 aaa'])
+  %s/aaa/\=Foo()/g
+  call assert_equal(['1 0', '2 0', '3 0'], getline(1, 3))
+
+  " Trow without try-catch causes abort after the first line.
+  " We cannot test this, since it would stop executing the test script.
+
+  " try/catch does not result in any changes
+  func! Foo()
+    throw 'error'
+  endfunc
+  call setline(1, ['1 aaa', '2 aaa', '3 aaa'])
+  let error_caught = 0
+  try
+    %s/aaa/\=Foo()/g
+  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