gnu: emacs-next-pgtk: Fix super key problem.

Recent version of emacs 29 with pgtk flag has a problem with handling super
key modifier, due to gtk bug: https://gitlab.gnome.org/GNOME/gtk/-/issues/4913
This commit workarounds it.

* gnu/packages/patches/emacs-pgtk-super-key-fix.patch: New file.
* gnu/packages/emacs.scm (emacs-next-pgtk): Use it here.
* gnu/local.mk (dist_patch_DATA): Register it here.

gnu/local.mk

@@ -1052,6 +1052,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/emacs-wordnut-require-adaptive-wrap.patch	\
   %D%/packages/patches/emacs-yasnippet-fix-tests.patch	\
   %D%/packages/patches/emacs-kv-fix-tests.patch	\
+  %D%/packages/patches/emacs-pgtk-super-key-fix.patch	\
   %D%/packages/patches/enjarify-setup-py.patch			\
   %D%/packages/patches/enlightenment-fix-setuid-path.patch	\
   %D%/packages/patches/erlang-man-path.patch			\

gnu/packages/emacs.scm

@@ -409,6 +409,10 @@ languages.")
   (package
     (inherit emacs-next)
     (name "emacs-next-pgtk")
+    (source
+     (origin
+       (inherit (package-source emacs-next))
+       (patches (search-patches "emacs-pgtk-super-key-fix.patch"))))
     (arguments
      (substitute-keyword-arguments (package-arguments emacs-next)
        ((#:configure-flags flags #~'())

gnu/packages/patches/emacs-pgtk-super-key-fix.patch

@@ -0,0 +1,49 @@
+From a897516fc5ec380938115ad42023f279d128fc1e Mon Sep 17 00:00:00 2001
+From: Andrew Tropin <andrew@trop.in>
+Date: Fri, 16 Sep 2022 15:24:19 +0300
+Subject: [PATCH] Workaround gtk bug for superkey handling
+
+https://gitlab.gnome.org/GNOME/gtk/-/issues/4913
+https://debbugs.gnu.org/cgi/bugreport.cgi?bug=55362
+Patch based on Thomas Jost's suggestion.
+
+---
+ src/pgtkterm.c | 9 +++++----
+ 1 file changed, 5 insertions(+), 4 deletions(-)
+
+diff --git a/src/pgtkterm.c b/src/pgtkterm.c
+index 491ba33882..d5a9970693 100644
+--- a/src/pgtkterm.c
++++ b/src/pgtkterm.c
+@@ -5051,7 +5051,7 @@ pgtk_gtk_to_emacs_modifiers (struct pgtk_display_info *dpyinfo, int state)
+     mod |= mod_ctrl;
+   if (state & GDK_META_MASK || state & GDK_MOD1_MASK)
+     mod |= mod_meta;
+-  if (state & GDK_SUPER_MASK)
++  if (state & GDK_SUPER_MASK || state & GDK_MOD4_MASK)
+     mod |= mod_super;
+   if (state & GDK_HYPER_MASK)
+     mod |= mod_hyper;
+@@ -5184,7 +5184,7 @@ key_press_event (GtkWidget *widget, GdkEvent *event, gpointer *user_data)
+       /* While super is pressed, the input method will always always
+ 	 resend the key events ignoring super.  As a workaround, don't
+ 	 filter key events with super or hyper pressed.  */
+-      if (!(event->key.state & (GDK_SUPER_MASK | GDK_HYPER_MASK)))
++      if (!(event->key.state & (GDK_SUPER_MASK | GDK_MOD4_MASK | GDK_HYPER_MASK)))
+ 	{
+ 	  if (pgtk_im_filter_keypress (f, &event->key))
+ 	    return TRUE;
+@@ -5199,8 +5199,9 @@ key_press_event (GtkWidget *widget, GdkEvent *event, gpointer *user_data)
+       /* make_lispy_event turns chars into control chars.
+          Don't do it here because XLookupString is too eager.  */
+       state &= ~GDK_CONTROL_MASK;
+-      state &= ~(GDK_META_MASK
+-		 | GDK_SUPER_MASK | GDK_HYPER_MASK | GDK_MOD1_MASK);
++      state &= ~(GDK_META_MASK | GDK_MOD1_MASK
++		 | GDK_SUPER_MASK | GDK_MOD4_MASK
++		 | GDK_HYPER_MASK);
+ 
+       nbytes = event->key.length;
+       if (nbytes > copy_bufsiz)
+-- 
+2.37.3