From 8fa32b3db5f40109489fe7455935b8887c0df89f Mon Sep 17 00:00:00 2001
From: Liang Chang <l-chang@users.sourceforge.net>
Date: Thu, 19 Aug 2021 07:17:51 +0800
Subject: [PATCH] dtwm: Trigger fullscreen in an "edge trigger" manner to avoid
 wrong behaviors caused by some unusual operations. E.g., after entered
 fullscreen, applications change windows to other states instead of leaving
 fullscreen.

---
 cde/programs/dtwm/WmCEvent.c   |  4 +++-
 cde/programs/dtwm/WmEwmh.c     |  8 +-------
 cde/programs/dtwm/WmGlobal.h   |  2 +-
 cde/programs/dtwm/WmManage.c   |  1 +
 cde/programs/dtwm/WmWinInfo.c  |  2 +-
 cde/programs/dtwm/WmWinState.c | 14 ++++++++++++--
 6 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/cde/programs/dtwm/WmCEvent.c b/cde/programs/dtwm/WmCEvent.c
index 9ce30f7ac..1245c9f65 100644
--- a/cde/programs/dtwm/WmCEvent.c
+++ b/cde/programs/dtwm/WmCEvent.c
@@ -2575,9 +2575,11 @@ void HandleClientMessage (ClientData *pCD, XClientMessageEvent *clientEvent)
 	}
 	else if (clientEvent->data.l[0] == NormalState)
 	{
-	    if (pCD->isFullscreen)
+	    if (pCD->enterFullscreen)
 	    {
+		Boolean enterFullscreen = pCD->enterFullscreen;
 		SetClientState (pCD, NORMAL_STATE, GetTimestamp ());
+		pCD->enterFullscreen = enterFullscreen;
 		newState = MAXIMIZED_STATE;
 	    }
 	    else
diff --git a/cde/programs/dtwm/WmEwmh.c b/cde/programs/dtwm/WmEwmh.c
index fbafdf9bb..0a1714fbf 100644
--- a/cde/programs/dtwm/WmEwmh.c
+++ b/cde/programs/dtwm/WmEwmh.c
@@ -149,16 +149,10 @@ static void ProcessNetWmStateFullscreen (ClientData *pCD, Boolean en)
 
     if (pHints != &hints) XFree (pHints);
 
-    pCD->isFullscreen = en;
+    pCD->enterFullscreen = en;
 
     XSendEvent (DISPLAY, ROOT_FOR_CLIENT (pCD), False, SubstructureRedirectMask,
 		(XEvent *) &clientMsgEvent);
-
-    if (en) XChangeProperty (DISPLAY, pCD->client, wmGD.xa_NET_WM_STATE,
-		    XA_ATOM, 32, PropModeReplace,
-		    (unsigned char *) &wmGD.xa_NET_WM_STATE_FULLSCREEN,
-		    1);
-    else XDeleteProperty (DISPLAY, pCD->client, wmGD.xa_NET_WM_STATE);
 } /* END OF FUNCTION ProcessNetWmStateFullscreen */
 
 
diff --git a/cde/programs/dtwm/WmGlobal.h b/cde/programs/dtwm/WmGlobal.h
index 891c4fb2e..e56e186fa 100644
--- a/cde/programs/dtwm/WmGlobal.h
+++ b/cde/programs/dtwm/WmGlobal.h
@@ -1629,7 +1629,7 @@ typedef struct _ClientData
     int		xBorderWidth;			/* original X border width */
     FrameInfo	frameInfo;			/* frame geometry data */
     Boolean	decorUpdated;			/* True => decoration updated */
-    Boolean	isFullscreen;			/* True => fullscreen */
+    Boolean	enterFullscreen;		/* True => enter fullscreen */
     Boolean	monitorSizeIsSet;		/* True => X, Y, W, H is set */
     int		monitorX;			/* monitor X loc */
     int		monitorY;			/* monitor Y loc */
diff --git a/cde/programs/dtwm/WmManage.c b/cde/programs/dtwm/WmManage.c
index a2347f5c3..0f23e002d 100644
--- a/cde/programs/dtwm/WmManage.c
+++ b/cde/programs/dtwm/WmManage.c
@@ -1008,6 +1008,7 @@ void WithdrawWindow (ClientData *pCD)
 	    }
 	}
 
+	XDeleteProperty (DISPLAY, pCD->client, wmGD.xa_NET_WM_STATE);
 	XUnmapWindow (DISPLAY, pCD->client);
 	XReparentWindow (DISPLAY, pCD->client, ROOT_FOR_CLIENT(pCD), x, y);
 
diff --git a/cde/programs/dtwm/WmWinInfo.c b/cde/programs/dtwm/WmWinInfo.c
index f1dc6d185..b6a816bb7 100644
--- a/cde/programs/dtwm/WmWinInfo.c
+++ b/cde/programs/dtwm/WmWinInfo.c
@@ -218,7 +218,7 @@ InitClientData (Window clientWindow)
     pCD->smClientID = (String)NULL;
 
     pCD->decorUpdated = False;
-    pCD->isFullscreen = False;
+    pCD->enterFullscreen = False;
     pCD->monitorSizeIsSet = False;
 
     return (pCD);
diff --git a/cde/programs/dtwm/WmWinState.c b/cde/programs/dtwm/WmWinState.c
index 22ab205c0..8ea2fab84 100644
--- a/cde/programs/dtwm/WmWinState.c
+++ b/cde/programs/dtwm/WmWinState.c
@@ -181,7 +181,6 @@ void SetClientStateWithEventMask (ClientData *pCD, int newState, Time setTime, u
 	     * WM_STATE property is set in WithdrawWindow.
 	     */
 
-	    XDeleteProperty (DISPLAY, pCD->client, wmGD.xa_NET_WM_STATE);
 	    UnManageWindow (pCD);
 	    break;
 	}
@@ -614,10 +613,12 @@ void ConfigureNewState (ClientData *pcd)
 	XResizeWindow (DISPLAY, pcd->client,
 			   (unsigned int) pcd->clientWidth, 
 			   (unsigned int) pcd->clientHeight);
+
+	XDeleteProperty (DISPLAY, pcd->client, wmGD.xa_NET_WM_STATE);
     }
     else
     {
-	if (pcd->isFullscreen && pcd->monitorSizeIsSet)
+	if (pcd->enterFullscreen && pcd->monitorSizeIsSet)
 	{
 	    pcd->maxX = pcd->monitorX;
 	    pcd->maxY = pcd->monitorY;
@@ -646,7 +647,16 @@ void ConfigureNewState (ClientData *pcd)
 			   (unsigned int) pcd->maxHeight);
 	pcd->maxConfig = TRUE;
 	RegenerateClientFrame(pcd);
+
+	if (pcd->enterFullscreen)
+	    XChangeProperty (DISPLAY, pcd->client, wmGD.xa_NET_WM_STATE,
+			    XA_ATOM, 32, PropModeReplace,
+			    (unsigned char *) &wmGD.xa_NET_WM_STATE_FULLSCREEN,
+			    1);
     }
+
+    pcd->enterFullscreen = False;
+
     SendConfigureNotify (pcd);
 
     /*