vim-patch:8.0.1304: CTRL-G/CTRL-T don't work with incsearch and empty pattern

Problem:    CTRL-G/CTRL-T don't work with incsearch and empty pattern.
Solution:   Use the last search pattern. (Christian Brabandt, closes vim/vim#2292)

d048009717

src/nvim/ex_getln.c

@@ -1019,7 +1019,16 @@ static void command_line_next_incsearch(CommandLineState *s, bool next_match)
   ui_flush();
 
   pos_T  t;
+  char_u *pat;
   int search_flags = SEARCH_NOOF;
+
+
+  if (s->firstc == ccline.cmdbuff[0]) {
+    pat = last_search_pattern();
+  } else {
+    pat = ccline.cmdbuff;
+  }
+
   save_last_search_pattern();
 
   if (next_match) {
@@ -1039,7 +1048,7 @@ static void command_line_next_incsearch(CommandLineState *s, bool next_match)
   emsg_off++;
   s->i = searchit(curwin, curbuf, &t,
                   next_match ? FORWARD : BACKWARD,
-                  ccline.cmdbuff, s->count, search_flags,
+                  pat, s->count, search_flags,
                   RE_SEARCH, 0, NULL);
   emsg_off--;
   ui_busy_stop();

src/nvim/search.c

@@ -335,6 +335,12 @@ restore_last_search_pattern(void)
   SET_NO_HLSEARCH(saved_no_hlsearch);
 }
 
+    char_u *
+last_search_pattern(void)
+{
+  return spats[RE_SEARCH].pat;
+}
+
 /*
  * Return TRUE when case should be ignored for search pattern "pat".
  * Uses the 'ignorecase' and 'smartcase' options.

src/nvim/version.c

@@ -193,7 +193,7 @@ static const int included_patches[] = {
   // 1307,
   // 1306,
   // 1305,
-  // 1304,
+  1304,
   // 1303,
   // 1302,
   // 1301,

test/functional/ui/searchhl_spec.lua

@@ -243,6 +243,30 @@ describe('search highlighting', function()
       {1:~                                       }|
       /^                                       |
     ]])
+
+    -- 8.0.1304, test that C-g and C-t works with incsearch and empty pattern
+    feed('<esc>/fi<CR>')
+    feed('//')
+    screen:expect([[
+        the {3:fi}rst line                        |
+        in a little {2:fi}le                      |
+                                              |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      //^                                      |
+    ]])
+
+    feed('<C-g>')
+    screen:expect([[
+        the {2:fi}rst line                        |
+        in a little {3:fi}le                      |
+                                              |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      //^                                      |
+    ]])
   end)
 
   it('works with incsearch and offset', function()