edge case: anon snip in pre-action

pythonx/UltiSnips/snippet_manager.py

@@ -8,6 +8,7 @@ from functools import wraps
 import os
 import platform
 import traceback
+from contextlib import contextmanager
 
 from UltiSnips import _vim
 from UltiSnips._diff import diff, guess_edit
@@ -95,6 +96,9 @@ class SnippetManager(object):
 
         self._snippet_sources = []
 
+        self._snip_expanded_in_action = False
+        self._inside_action = False
+
         self._added_snippets_source = AddedSnippetsSource()
         self.register_snippet_source('ultisnips_files', UltiSnipsFileSource())
         self.register_snippet_source('added', self._added_snippets_source)
@@ -586,12 +590,15 @@ class SnippetManager(object):
         done with it."""
         self._setup_inner_state()
 
+        self._snip_expanded_in_action = False
+
         # Adjust before, maybe the trigger is not the complete word
         text_before = before
         if snippet.matched:
             text_before = before[:-len(snippet.matched)]
 
         with use_proxy_buffer(self._csnippets):
+            with self._action_context():
                 cursor_set_in_action = snippet.do_pre_expand(
                     self._visual_content.text,
                     self._csnippets
@@ -637,13 +644,23 @@ class SnippetManager(object):
             si.update_textobjects()
 
             with use_proxy_buffer(self._csnippets):
+                with self._action_context():
                     snippet.do_post_expand(
                         si._start, si._end, self._csnippets
                     )
 
             self._vstate.remember_buffer(self._csnippets[0])
 
+            if not self._snip_expanded_in_action:
                 self._jump()
+            elif self._cs.current_text != '':
+                self._jump()
+            else:
+                self._current_snippet_is_done()
+
+            if self._inside_action:
+                self._snip_expanded_in_action = True
+
 
     def _try_expand(self):
         """Try to expand a snippet in the current place."""
@@ -733,3 +750,12 @@ class SnippetManager(object):
         if not os.path.exists(dirname):
             os.makedirs(dirname)
         return file_to_edit
+
+    @contextmanager
+    def _action_context(self):
+        try:
+            old_flag = self._inside_action
+            self._inside_action = True
+            yield
+        finally:
+            self._inside_action = old_flag

test/test_SnippetActions.py

@@ -307,3 +307,12 @@ class SnippetActions_CanEvenWrapSnippetInPreAction(_VimTest):
         """}
     keys = "test" + EX + "1" + JF + "2" + JF + "3" + JF + "4"
     wanted = """some_wrapper(wrapme(2, 1)3): 4"""
+
+class SnippetActions_CanVisuallySelectFirstPlaceholderInAnonSnippetInPre(_VimTest):
+    files = { 'us/all.snippets': r"""
+        pre_expand "snip.buffer[snip.line] = ''; snip.expand_anon('${1:asd}, ${2:blah}')"
+        snippet test "test new features" wb
+        endsnippet
+        """}
+    keys = "test" + EX + "1" + JF + "2"
+    wanted = """1, 2"""