vim-patch:8.2.4579: cannot use page-up and page-down in the cmdline popup menu

Problem:    Cannot use page-up and page-down in the command line completion
            popup menu.
Solution:   Check for to page-up and page-down keys. (Yegappan Lakshmanan,
            closes vim/vim#9960)

https://github.com/vim/vim/commit/5cffa8df7e3c28681b9e5deef6df395784359b6b

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

5 files changed, 231 insertions, 14 deletions

diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index 422649b67b..a1f15fabb6 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -217,7 +217,9 @@ int nextwild(expand_T *xp, int type, int options, bool escape)
   assert(ccline->cmdpos >= i);
   xp->xp_pattern_len = (size_t)ccline->cmdpos - (size_t)i;
 
-  if (type == WILD_NEXT || type == WILD_PREV || type == WILD_PUM_WANT) {
+  if (type == WILD_NEXT || type == WILD_PREV
+      || type == WILD_PAGEUP || type == WILD_PAGEDOWN
+      || type == WILD_PUM_WANT) {
     // Get next/previous match for a previous expanded pattern.
     p2 = ExpandOne(xp, NULL, NULL, 0, type);
   } else {
@@ -593,6 +595,44 @@ static char *get_next_or_prev_match(int mode, expand_T *xp, int *p_findex, char
     findex--;
   } else if (mode == WILD_NEXT) {
     findex++;
+  } else if (mode == WILD_PAGEUP) {
+    if (findex == 0) {
+      // at the first entry, don't select any entries
+      findex = -1;
+    } else if (findex == -1) {
+      // no entry is selected. select the last entry
+      findex = xp->xp_numfiles - 1;
+    } else {
+      // go up by the pum height
+      int ht = pum_get_height();
+      if (ht > 3) {
+        ht -= 2;
+      }
+      findex -= ht;
+      if (findex < 0) {
+        // few entries left, select the first entry
+        findex = 0;
+      }
+    }
+  } else if (mode == WILD_PAGEDOWN) {
+    if (findex == xp->xp_numfiles - 1) {
+      // at the last entry, don't select any entries
+      findex = -1;
+    } else if (findex == -1) {
+      // no entry is selected. select the first entry
+      findex = 0;
+    } else {
+      // go down by the pum height
+      int ht = pum_get_height();
+      if (ht > 3) {
+        ht -= 2;
+      }
+      findex += ht;
+      if (findex >= xp->xp_numfiles) {
+        // few entries left, select the last entry
+        findex = xp->xp_numfiles - 1;
+      }
+    }
   } else {  // mode == WILD_PUM_WANT
     assert(pum_want.active);
     findex = pum_want.item;
@@ -770,7 +810,9 @@ char *ExpandOne(expand_T *xp, char *str, char *orig, int options, int mode)
   int i;
 
   // first handle the case of using an old match
-  if (mode == WILD_NEXT || mode == WILD_PREV || mode == WILD_PUM_WANT) {
+  if (mode == WILD_NEXT || mode == WILD_PREV
+      || mode == WILD_PAGEUP || mode == WILD_PAGEDOWN
+      || mode == WILD_PUM_WANT) {
     return get_next_or_prev_match(mode, xp, &findex, orig_save);
   }
 
diff --git a/src/nvim/cmdexpand.h b/src/nvim/cmdexpand.h
index cdd6192086..810e289f7c 100644
--- a/src/nvim/cmdexpand.h
+++ b/src/nvim/cmdexpand.h
@@ -19,8 +19,8 @@ enum {
   WILD_ALL_KEEP    = 8,
   WILD_CANCEL      = 9,
   WILD_APPLY       = 10,
-  // WILD_PAGEUP   = 11, not ported yet
-  // WILD_PAGEDOWN = 12, not ported yet
+  WILD_PAGEUP      = 11,
+  WILD_PAGEDOWN    = 12,
   WILD_PUM_WANT    = 13,
 };
 
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 72208c976f..fc227f357e 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -1234,10 +1234,20 @@ static int command_line_execute(VimState *state, int key)
     }
   }
 
+  // The wildmenu is cleared if the pressed key is not used for
+  // navigating the wild menu (i.e. the key is not 'wildchar' or
+  // 'wildcharm' or Ctrl-N or Ctrl-P or Ctrl-A or Ctrl-L).
+  // If the popup menu is displayed, then PageDown and PageUp keys are
+  // also used to navigate the menu.
+  bool end_wildmenu = (!(s->c == p_wc && KeyTyped) && s->c != p_wcm && s->c != Ctrl_Z
+                       && s->c != Ctrl_N && s->c != Ctrl_P && s->c != Ctrl_A
+                       && s->c != Ctrl_L);
+  end_wildmenu = end_wildmenu && (!cmdline_pum_active()
+                                  || (s->c != K_PAGEDOWN && s->c != K_PAGEUP
+                                      && s->c != K_KPAGEDOWN && s->c != K_KPAGEUP));
+
   // free expanded names when finished walking through matches
-  if (!(s->c == p_wc && KeyTyped) && s->c != p_wcm && s->c != Ctrl_Z
-      && s->c != Ctrl_N && s->c != Ctrl_P && s->c != Ctrl_A
-      && s->c != Ctrl_L) {
+  if (end_wildmenu) {
     command_line_end_wildmenu(s);
   }
 
@@ -2016,13 +2026,26 @@ static int command_line_handle_key(CommandLineState *s)
   case K_KPAGEUP:
   case K_PAGEDOWN:
   case K_KPAGEDOWN:
-    switch (command_line_browse_history(s)) {
-    case CMDLINE_CHANGED:
-      return command_line_changed(s);
-    case GOTO_NORMAL_MODE:
-      return 0;
-    default:
+    if (cmdline_pum_active()
+        && (s->c == K_PAGEUP || s->c == K_PAGEDOWN
+            || s->c == K_KPAGEUP || s->c == K_KPAGEDOWN)) {
+      // If the popup menu is displayed, then PageUp and PageDown
+      // are used to scroll the menu.
+      if (nextwild(&s->xpc,
+                   (s->c == K_PAGEUP) ? WILD_PAGEUP : WILD_PAGEDOWN,
+                   0, s->firstc != '@') == FAIL) {
+        break;
+      }
       return command_line_not_changed(s);
+    } else {
+      switch (command_line_browse_history(s)) {
+      case CMDLINE_CHANGED:
+        return command_line_changed(s);
+      case GOTO_NORMAL_MODE:
+        return 0;
+      default:
+        return command_line_not_changed(s);
+      }
     }
 
   case Ctrl_G:  // next match
diff --git a/src/nvim/testdir/test_cmdline.vim b/src/nvim/testdir/test_cmdline.vim
index 75bcc575d3..50bdfceebd 100644
--- a/src/nvim/testdir/test_cmdline.vim
+++ b/src/nvim/testdir/test_cmdline.vim
@@ -151,6 +151,14 @@ func Test_complete_wildmenu()
   call assert_equal('"e Xdir1/Xdir2/1', @:)
   cunmap <F2>
 
+  " Test for canceling the wild menu by pressing <PageDown> or <PageUp>.
+  " After this pressing <Left> or <Right> should not change the selection.
+  call feedkeys(":sign \<Tab>\<PageDown>\<Left>\<Right>\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"sign define', @:)
+  call histadd('cmd', 'TestWildMenu')
+  call feedkeys(":sign \<Tab>\<PageUp>\<Left>\<Right>\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"TestWildMenu', @:)
+
   " cleanup
   %bwipe
   call delete('Xdir1', 'rf')
@@ -2539,6 +2547,28 @@ func Test_wildmenu_pum()
   call VerifyScreenDump(buf, 'Test_wildmenu_pum_41', {})
   call term_sendkeys(buf, "\<Esc>")
 
+  " Pressing <PageDown> should scroll the menu downward
+  call term_sendkeys(buf, ":sign \<Tab>\<PageDown>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_42', {})
+  call term_sendkeys(buf, "\<PageDown>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_43', {})
+  call term_sendkeys(buf, "\<PageDown>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_44', {})
+  call term_sendkeys(buf, "\<PageDown>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_45', {})
+  call term_sendkeys(buf, "\<C-U>sign \<Tab>\<Down>\<Down>\<PageDown>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_46', {})
+
+  " Pressing <PageUp> should scroll the menu upward
+  call term_sendkeys(buf, "\<C-U>sign \<Tab>\<PageUp>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_47', {})
+  call term_sendkeys(buf, "\<PageUp>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_48', {})
+  call term_sendkeys(buf, "\<PageUp>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_49', {})
+  call term_sendkeys(buf, "\<PageUp>")
+  call VerifyScreenDump(buf, 'Test_wildmenu_pum_50', {})
+
   call term_sendkeys(buf, "\<C-U>\<CR>")
   call StopVimInTerminal(buf)
   call delete('Xtest')
diff --git a/test/functional/ui/popupmenu_spec.lua b/test/functional/ui/popupmenu_spec.lua
index 78b2f52c1f..85e6a03872 100644
--- a/test/functional/ui/popupmenu_spec.lua
+++ b/test/functional/ui/popupmenu_spec.lua
@@ -2388,8 +2388,130 @@ describe('builtin popupmenu', function()
       {1:~        }{n: xyz            }{1:       }|
       :e あいう/123^                   |
     ]])
+    feed('<Esc>')
 
-    feed('<esc>')
+    -- Pressing <PageDown> should scroll the menu downward
+    feed(':sign <Tab><PageDown>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{n: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{s: undefine       }{1:           }|
+      {1:~    }{n: unplace        }{1:           }|
+      :sign undefine^                  |
+    ]])
+    feed('<PageDown>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{n: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{s: unplace        }{1:           }|
+      :sign unplace^                   |
+    ]])
+    feed('<PageDown>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{n: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{n: unplace        }{1:           }|
+      :sign ^                          |
+    ]])
+    feed('<PageDown>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{s: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{n: unplace        }{1:           }|
+      :sign define^                    |
+    ]])
+    feed('<C-U>sign <Tab><Right><Right><PageDown>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{n: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{s: unplace        }{1:           }|
+      :sign unplace^                   |
+    ]])
+
+    -- Pressing <PageUp> should scroll the menu upward
+    feed('<C-U>sign <Tab><PageUp>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{n: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{n: unplace        }{1:           }|
+      :sign ^                          |
+    ]])
+    feed('<PageUp>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{n: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{s: unplace        }{1:           }|
+      :sign unplace^                   |
+    ]])
+    feed('<PageUp>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{n: define         }{1:           }|
+      {1:~    }{s: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{n: unplace        }{1:           }|
+      :sign jump^                      |
+    ]])
+    feed('<PageUp>')
+    screen:expect([[
+                                      |
+      {1:~                               }|
+      {1:~                               }|
+      {1:~    }{s: define         }{1:           }|
+      {1:~    }{n: jump           }{1:           }|
+      {1:~    }{n: list           }{1:           }|
+      {1:~    }{n: place          }{1:           }|
+      {1:~    }{n: undefine       }{1:           }|
+      {1:~    }{n: unplace        }{1:           }|
+      :sign define^                    |
+    ]])
+
+    feed('<Esc>')
 
     -- check positioning with multibyte char in pattern
     command("e långfile1")