LCL-GTK1: Fix various startup warnings and Gtk1 assertions

This fixes a bunch of warnings when Gtk1 applications start.  The fixes
are on keyboard initialization (make a previously statically sized array
dynamic as the old value wasn't long enough and disable an unnecessary
warning about filling the VK table as the user can't do anything about
it - nor we unless the whole thing is redesigned), module loading (this
is a side effect of an environment variable collision between Gtk1, Gtk2
and Gtk3 - all of these use the GTK_MODULES variable to load some
modules but since as of 2023 no distribution aside from Slackware comes
with Gtk1, all of these warnings are bogus, so this patch temporarily
cleans the environment variable before initializing Gtk and restores it
later so that child processes can still access it) and passing NULL
styles to gtk_style_copy (the previous code assumed the style retrieval
functions always return a valid object, which is not the case).

lcl/interfaces/gtk/gtk1widgetset.inc

@@ -37,10 +37,13 @@ begin
     Exit; // the GTKAPIWidget is self drawn, so no use to change the widget style.
 
   if (GTK_WIDGET_REALIZED(AWidget)) then
-    WindowStyle := gtk_style_copy(gtk_widget_get_style(AWidget))
+    WindowStyle := gtk_widget_get_style(AWidget)
   else
-    WindowStyle := gtk_style_copy(gtk_rc_get_style(AWidget));
-    
+    WindowStyle := gtk_rc_get_style(AWidget);
+
+  if WindowStyle <> nil then
+    WindowStyle := gtk_style_copy(WindowStyle);
+
   if (Windowstyle = nil) then
     Windowstyle := gtk_style_new;
 

lcl/interfaces/gtk/gtkdefines.inc

@@ -33,8 +33,22 @@
 
 {off $Define Disable_GC_SysColors}
 
+{$define HideKeyTableWarnings}
+
 {$define RawimageConsistencyChecks}
 
+(*
+ Gtk1 uses a GTK_MODULES environment variable that causes it to load modules
+ at startup, however this variable is also used by Gtk2 and Gtk3, meaning
+ that if a referenced module is not part of the available Gtk1 modules the
+ program will display a warning at startup time.  Since as of 2023 pretty much
+ no distribution comes with Gtk1 this is always a bogus warning and to avoid
+ this, the GTK_MODULES environment variable will be cleaned during startup and
+ reset after the toolkit has been initialized to allow for Gtk2 and later child
+ processes.
+*)
+{$define ClearGtkModulesEnvVar}
+
 (*
  keep track of keystates instead of using OS
  This is the old mode and might be removed

lcl/interfaces/gtk/gtkproc.inc

@@ -3193,7 +3193,7 @@ var
   XKeyEvent: TXKeyEvent;
   KeySymStart, KeySymNext: PKeySym;
   UpKeySym, LoKeySym: TKeySym;
-  KeySyms: array of TKeySym;
+  KeySyms: array of TKeySym = nil;
 {$else}
   KeySyms: array of guint;
   KeyVals: Pguint;
@@ -3214,7 +3214,7 @@ var
 
   KeyCode: Byte;
   m: Integer;
-  LoKey, HiKey: Integer;
+  LoKey, HiKey, I: Integer;
 
   VKey, FreeVK: Byte;
   HasMultiVK, DummyBool, Extended, SecondKey, HasKey, ComputeVK: Boolean;
@@ -3258,8 +3258,14 @@ begin
     then XFree(KeySymStart);
     Exit;
   end;
-  if KeySymCount > Length(MVKeyInfo[0].KeySym)
-  then DebugLn('[WARNING] keysymcount=%u larger than expected=%u', [KeySymCount, Length(MVKeyInfo[0].KeySym)]);
+  // The code in Accelerate below assumes at least 2 items in the KeySym array
+  if KeySymCount > 2 then begin
+    for I:=Low(MVKeyInfo) to High(MVKeyInfo) do
+      SetLength(MVKeyInfo[I].KeySym, KeySymCount);
+  end else begin
+    for I:=Low(MVKeyInfo) to High(MVKeyInfo) do
+      SetLength(MVKeyInfo[I].KeySym, 2);
+  end;
   SetLength(KeySyms, KeySymCount);
 {$else gtk1}
   LoKey := 0;

lcl/interfaces/gtk/gtkproc.pp

@@ -417,7 +417,7 @@ type
   TVKeyUTF8Char = array[0..7] of Char;
   TVKeyInfo = record
     KeyCode: array[Boolean] of Byte; // false is primary keycode, true the keycode of the other key when 2 keys exist (like CTRL or extended key)
-    KeySym: array[0..7] of Integer;
+    KeySym: array of Integer;
     KeyChar: array[0..3] of TVKeyUTF8Char;
   end;
 

lcl/interfaces/gtk/gtkwidgetset.inc

@@ -148,6 +148,10 @@ begin
   fpsigaction(SIGCHLD, @child_action, nil);
 end;
 
+{$ifdef ClearGtkModulesEnvVar}
+function setenv(envname, envvar: PAnsiChar; overwrite: cint): cint; cdecl; external 'c' name 'setenv';
+{$endif}
+
 {$endif}
 
 {------------------------------------------------------------------------------
@@ -164,6 +168,10 @@ var
   TM: TThreadManager;
 {$ENDIF}
 {$ENDIF}
+{$ifdef ClearGtkModulesEnvVar}
+var
+  OldGtkModulesValue: AnsiString;
+{$endif}
 begin
   if ClassType = TGtkWidgetSet
   then raise EInvalidOperation.Create('Cannot create the base gtkwidgetset, use gtk1 or gtk2 instead');
@@ -226,9 +234,20 @@ begin
   // initialize app level gtk engine
   gtk_set_locale ();
 
+  // clear the GTK_MODULES environment variable if needed
+  {$ifdef ClearGtkModulesEnvVar}
+  OldGtkModulesValue:=GetEnvironmentVariable('GTK_MODULES');
+  setenv('GTK_MODULES', '', 1);
+  {$endif}
+
   // call init and pass cmd line args
   PassCmdLineOptions;
 
+  // restore the GTK_MODULES environment variable
+  {$ifdef ClearGtkModulesEnvVar}
+  setenv('GTK_MODULES', PAnsiChar(OldGtkModulesValue), 1);
+  {$endif}
+
   // set glib log handler
   FLogHandlerID := g_log_set_handler(nil, -1, @GLogFunc, Self);
 
@@ -1054,9 +1073,11 @@ begin
   {$ENDIF}
   
   if (GTK_WIDGET_REALIZED(AWidget)) then
-    WindowStyle := gtk_style_copy(gtk_widget_get_style(AWidget))
+    WindowStyle := gtk_widget_get_style(AWidget)
   else
-    WindowStyle := gtk_style_copy(gtk_rc_get_style(AWidget));
+    WindowStyle := gtk_rc_get_style(AWidget);
+
+  if WindowStyle <> nil then WindowStyle := gtk_style_copy(WindowStyle);
 
   if (Windowstyle = nil) then
     Windowstyle := gtk_style_new;
@@ -3791,6 +3812,11 @@ begin
     LM_DROPFILES:
       ConnectSenderSignal(gCore, 'drag_data_received', @GtkDragDataReceived);
 
+    LM_CONTEXTMENU:
+    begin
+      // Gtk1 does not have an explicit context menu signal, LM_CONTEXTMENU
+      // support is emulated in gtkMouseBtnPress
+    end;
 (*
     LM_WINDOWPOSCHANGED:
     begin