diff --git a/src/Makefile b/src/Makefile
index 1589fba..fd07946 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2047,7 +2047,7 @@
 	test40 test41 test42 test43 test44 test45 test48 test49 \
 	test50 test51 test52 test53 test54 test55 test56 test57 test58 test59 \
 	test60 test64 test65 test66 test67 test68 test69 \
-	test70 test72 test73 test74 test75 test76 test77 test78 test79 \
+	test70 test72 test73 test74 test75 test77 test78 test79 \
 	test80 test82 test83 test84 test85 test86 test87 test88 test89 \
 	test90 test91 test92 test93 test94 test95 test97 test98 test99 \
 	test100 test101 test103 test104 test107 test108:
diff --git a/src/edit.c b/src/edit.c
index a87c155..d763b53 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -179,8 +179,8 @@
 #endif
 static int  ins_compl_get_exp(pos_T *ini);
 static void ins_compl_delete(void);
-static void ins_compl_insert(void);
-static int  ins_compl_next(int allow_get_expansion, int count, int insert_match);
+static void ins_compl_insert(int in_compl_func);
+static int  ins_compl_next(int allow_get_expansion, int count, int insert_match, int in_compl_func);
 static int  ins_compl_key2dir(int c);
 static int  ins_compl_pum_key(int c);
 static int  ins_compl_key2count(int c);
@@ -861,7 +861,7 @@
 				   && (c == CAR || c == K_KENTER || c == NL)))
 		{
 		    ins_compl_delete();
-		    ins_compl_insert();
+		    ins_compl_insert(FALSE);
 		}
 	    }
 	}
@@ -3297,7 +3297,7 @@
 			break;
 		}
 		line_breakcheck();
-		ins_compl_check_keys(50);
+		ins_compl_check_keys(50, FALSE);
 	    }
 	    fclose(fp);
 	}
@@ -4036,8 +4036,6 @@
 }
 
 #ifdef FEAT_COMPL_FUNC
-static void expand_by_function(int type, char_u *base);
-
 /*
  * Execute user defined complete function 'completefunc' or 'omnifunc', and
  * get matches in "matches".
@@ -4596,7 +4594,7 @@
 		break;
 	    /* Fill the popup menu as soon as possible. */
 	    if (type != -1)
-		ins_compl_check_keys(0);
+		ins_compl_check_keys(0, FALSE);
 
 	    if ((ctrl_x_mode != 0 && !CTRL_X_MODE_LINE_OR_EVAL(ctrl_x_mode))
 							 || compl_interrupted)
@@ -4653,9 +4651,12 @@
     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc());
 }
 
-/* Insert the new text being completed. */
+/*
+ * Insert the new text being completed.
+ * "in_compl_func" is TRUE when called from complete_check().
+ */
     static void
-ins_compl_insert(void)
+ins_compl_insert(int in_compl_func)
 {
     dict_T	*dict;
 
@@ -4682,7 +4683,8 @@
 		    EMPTY_IF_NULL(compl_shown_match->cp_text[CPT_INFO]));
     }
     set_vim_var_dict(VV_COMPLETED_ITEM, dict);
-    compl_curr_match = compl_shown_match;
+    if (!in_compl_func)
+	compl_curr_match = compl_shown_match;
 }
 
 /*
@@ -4706,7 +4708,8 @@
     int	    allow_get_expansion,
     int	    count,		/* repeat completion this many times; should
 				   be at least 1 */
-    int	    insert_match)	/* Insert the newly selected match */
+    int	    insert_match,	/* Insert the newly selected match */
+    int	    in_compl_func)	/* called from complete_check() */
 {
     int	    num_matches = -1;
     int	    i;
@@ -4856,7 +4859,7 @@
     else if (insert_match)
     {
 	if (!compl_get_longest || compl_used_match)
-	    ins_compl_insert();
+	    ins_compl_insert(in_compl_func);
 	else
 	    ins_bytes(compl_leader + ins_compl_len());
     }
@@ -4921,9 +4924,11 @@
  * mode.  Also, when compl_pending is not zero, show a completion as soon as
  * possible. -- webb
  * "frequency" specifies out of how many calls we actually check.
+ * "in_compl_func" is TRUE when called from complete_check(), don't set
+ * compl_curr_match.
  */
     void
-ins_compl_check_keys(int frequency)
+ins_compl_check_keys(int frequency, int in_compl_func)
 {
     static int	count = 0;
 
@@ -4949,7 +4954,7 @@
 	    c = safe_vgetc();	/* Eat the character */
 	    compl_shows_dir = ins_compl_key2dir(c);
 	    (void)ins_compl_next(FALSE, ins_compl_key2count(c),
-						    c != K_UP && c != K_DOWN);
+				      c != K_UP && c != K_DOWN, in_compl_func);
 	}
 	else
 	{
@@ -4972,7 +4977,7 @@
 	int todo = compl_pending > 0 ? compl_pending : -compl_pending;
 
 	compl_pending = 0;
-	(void)ins_compl_next(FALSE, todo, TRUE);
+	(void)ins_compl_next(FALSE, todo, TRUE, in_compl_func);
     }
 }
 
@@ -5490,7 +5495,8 @@
      * Find next match (and following matches).
      */
     save_w_wrow = curwin->w_wrow;
-    n = ins_compl_next(TRUE, ins_compl_key2count(c), ins_compl_use_match(c));
+    n = ins_compl_next(TRUE, ins_compl_key2count(c),
+						ins_compl_use_match(c), FALSE);
 
     /* may undisplay the popup menu */
     ins_compl_upd_pum();
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 9fa8f1c..f643329 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -2175,7 +2175,7 @@
     int		saved = RedrawingDisabled;
 
     RedrawingDisabled = 0;
-    ins_compl_check_keys(0);
+    ins_compl_check_keys(0, TRUE);
     rettv->vval.v_number = compl_interrupted;
     RedrawingDisabled = saved;
 }
diff --git a/src/proto/edit.pro b/src/proto/edit.pro
index e32b5ba..7a399c0 100644
--- a/src/proto/edit.pro
+++ b/src/proto/edit.pro
@@ -15,7 +15,7 @@
 char_u *find_word_end(char_u *ptr);
 int ins_compl_active(void);
 int ins_compl_add_tv(typval_T *tv, int dir);
-void ins_compl_check_keys(int frequency);
+void ins_compl_check_keys(int frequency, int in_compl_func);
 int get_literal(void);
 void insertchar(int c, int flags, int second_indent);
 void auto_format(int trailblank, int prev_line);
diff --git a/src/search.c b/src/search.c
index cb5caeb..cedcad9 100644
--- a/src/search.c
+++ b/src/search.c
@@ -5429,7 +5429,7 @@
 	line_breakcheck();
 #ifdef FEAT_INS_EXPAND
 	if (action == ACTION_EXPAND)
-	    ins_compl_check_keys(30);
+	    ins_compl_check_keys(30, FALSE);
 	if (got_int || compl_interrupted)
 #else
 	if (got_int)
diff --git a/src/spell.c b/src/spell.c
index 69ac6df..eb81ad2 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -8694,7 +8694,7 @@
 		    /* Done all bytes at this node, go up one level. */
 		    --depth;
 		    line_breakcheck();
-		    ins_compl_check_keys(50);
+		    ins_compl_check_keys(50, FALSE);
 		}
 		else
 		{
diff --git a/src/tag.c b/src/tag.c
index d679686..14fdcf8 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -1587,7 +1587,7 @@
 		fast_breakcheck();
 #ifdef FEAT_INS_EXPAND
 	    if ((flags & TAG_INS_COMP))	/* Double brackets for gcc */
-		ins_compl_check_keys(30);
+		ins_compl_check_keys(30, FALSE);
 	    if (got_int || compl_interrupted)
 #else
 	    if (got_int)
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index a997580..a8ea543 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -55,7 +55,6 @@
 	test70.out \
 	test73.out \
 	test75.out \
-	test76.out \
 	test77.out \
 	test79.out \
 	test80.out \
diff --git a/src/testdir/test76.in b/src/testdir/test76.in
deleted file mode 100644
index db7ebe2..0000000
--- a/src/testdir/test76.in
+++ /dev/null
@@ -1,46 +0,0 @@
-Tests for completefunc/omnifunc. vim: set ft=vim :
-
-STARTTEST
-:"Test that nothing happens if the 'completefunc' opens
-:"a new window (no completion, no crash)
-:so small.vim
-:function! DummyCompleteOne(findstart, base)
-:  if a:findstart
-:    return 0
-:  else
-:    wincmd n
-:    return ['onedef', 'oneDEF']
-:  endif
-:endfunction
-:setlocal completefunc=DummyCompleteOne
-/^one
-A:q!
-:function! DummyCompleteTwo(findstart, base)
-:  if a:findstart
-:    wincmd n
-:    return 0
-:  else
-:    return ['twodef', 'twoDEF']
-:  endif
-:endfunction
-:setlocal completefunc=DummyCompleteTwo
-/^two
-A:q!
-:"Test that 'completefunc' works when it's OK.
-:function! DummyCompleteThree(findstart, base)
-:  if a:findstart
-:    return 0
-:  else
-:    return ['threedef', 'threeDEF']
-:  endif
-:endfunction
-:setlocal completefunc=DummyCompleteThree
-/^three
-A:/^+++/,/^three/w! test.out
-:qa!
-ENDTEST
-
-+++
-one
-two
-three
diff --git a/src/testdir/test76.ok b/src/testdir/test76.ok
deleted file mode 100644
index 2a70acb..0000000
--- a/src/testdir/test76.ok
+++ /dev/null
@@ -1,4 +0,0 @@
-+++
-
-two
-threeDEF
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 10eaf3a..7cb0e10 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -289,4 +289,115 @@
   bwipe!
 endfunc
 
+func DummyCompleteOne(findstart, base)
+  if a:findstart
+    return 0
+  else
+    wincmd n
+    return ['onedef', 'oneDEF']
+  endif
+endfunc
+
+" Test that nothing happens if the 'completefunc' opens
+" a new window (no completion, no crash)
+func Test_completefunc_opens_new_window_one()
+  new
+  let winid = win_getid()
+  setlocal completefunc=DummyCompleteOne
+  call setline(1, 'one')
+  /^one
+  call assert_fails('call feedkeys("A\<C-X>\<C-U>\<C-N>\<Esc>", "x")', 'E839:')
+  call assert_notequal(winid, win_getid())
+  q!
+  call assert_equal(winid, win_getid())
+  call assert_equal('', getline(1))
+  q!
+endfunc
+
+" Test that nothing happens if the 'completefunc' opens
+" a new window (no completion, no crash)
+func DummyCompleteTwo(findstart, base)
+  if a:findstart
+    wincmd n
+    return 0
+  else
+    return ['twodef', 'twoDEF']
+  endif
+endfunction
+
+" Test that nothing happens if the 'completefunc' opens
+" a new window (no completion, no crash)
+func Test_completefunc_opens_new_window_two()
+  new
+  let winid = win_getid()
+  setlocal completefunc=DummyCompleteTwo
+  call setline(1, 'two')
+  /^two
+  call assert_fails('call feedkeys("A\<C-X>\<C-U>\<C-N>\<Esc>", "x")', 'E764:')
+  call assert_notequal(winid, win_getid())
+  q!
+  call assert_equal(winid, win_getid())
+  call assert_equal('two', getline(1))
+  q!
+endfunc
+
+func DummyCompleteThree(findstart, base)
+  if a:findstart
+    return 0
+  else
+    return ['threedef', 'threeDEF']
+  endif
+endfunc
+
+:"Test that 'completefunc' works when it's OK.
+func Test_completefunc_works()
+  new
+  let winid = win_getid()
+  setlocal completefunc=DummyCompleteThree
+  call setline(1, 'three')
+  /^three
+  call feedkeys("A\<C-X>\<C-U>\<C-N>\<Esc>", "x")
+  call assert_equal(winid, win_getid())
+  call assert_equal('threeDEF', getline(1))
+  q!
+endfunc
+
+func DummyCompleteFour(findstart, base)
+  if a:findstart
+    return 0
+  else
+    call complete_add('four1')
+    call complete_add('four2')
+    call complete_check()
+    call complete_add('four3')
+    call complete_add('four4')
+    call complete_check()
+    call complete_add('four5')
+    call complete_add('four6')
+    return []
+  endif
+endfunc
+
+:"Test that 'completefunc' works when it's OK.
+func Test_omnifunc_with_check()
+  new
+  setlocal omnifunc=DummyCompleteFour
+  call setline(1, 'four')
+  /^four
+  call feedkeys("A\<C-X>\<C-O>\<C-N>\<Esc>", "x")
+  call assert_equal('four2', getline(1))
+
+  call setline(1, 'four')
+  /^four
+  call feedkeys("A\<C-X>\<C-O>\<C-N>\<C-N>\<Esc>", "x")
+  call assert_equal('four3', getline(1))
+
+  call setline(1, 'four')
+  /^four
+  call feedkeys("A\<C-X>\<C-O>\<C-N>\<C-N>\<C-N>\<C-N>\<Esc>", "x")
+  call assert_equal('four5', getline(1))
+
+  q!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index e803bae..513223e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    35,
+/**/
     34,
 /**/
     33,