[PATCH] xf86RandR12: Don't call ConstrainCursorHarder() if panning is enabled

[Rui Matos]

Panning is at odds with CRTC cursor confinement. This disables CRTC cursor
confinement as long as panning is enabled.

Fixes regression introduced in 56c90e29f04727c903bd0f084d23bf44eb1a0a11.

Signed-off-by: Rui Matos <tiagomatos at gmail.com>
---
 hw/xfree86/modes/xf86RandR12.c |   37 +++++++++++++++++++++++++++++++++++--
 1 files changed, 35 insertions(+), 2 deletions(-)

v3: Although this approach isn't semantically equivalent to the previous since
    it completely disables CRTC cursor confinement while panning is enabled I
    prefer it because it's shorter, cleaner and contained in a single file.

    Anyway, panning still keeps working as it did, though not benefiting from
    CRTC cursor confinement as it could. But, people using panning (are there
    any?) surely know what they're doing.

diff --git a/hw/xfree86/modes/xf86RandR12.c b/hw/xfree86/modes/xf86RandR12.c
index 57b3b0e..426d8f4 100644
--- a/hw/xfree86/modes/xf86RandR12.c
+++ b/hw/xfree86/modes/xf86RandR12.c
@@ -60,6 +60,9 @@ typedef struct _xf86RandR12Info {
      * See https://bugs.freedesktop.org/show_bug.cgi?id=21554
      */
     xf86EnterVTProc *orig_EnterVT;
+
+    Bool                         panning;
+    ConstrainCursorHarderProcPtr orig_ConstrainCursorHarder;
 } XF86RandRInfoRec, *XF86RandRInfoPtr;
 
 #ifdef RANDR_12_INTERFACE
@@ -74,6 +77,9 @@ static DevPrivateKey xf86RandR12Key;
 #define XF86RANDRINFO(p) ((XF86RandRInfoPtr) \
     dixLookupPrivate(&(p)->devPrivates, xf86RandR12Key))
 
+#define PANNING_ENABLED(crtc)                                           \
+    ((crtc)->panningTotalArea.x2 > (crtc)->panningTotalArea.x1 ||       \
+     (crtc)->panningTotalArea.y2 > (crtc)->panningTotalArea.y1)
 
 static int
 xf86RandR12ModeRefresh (DisplayModePtr mode)
@@ -687,6 +693,7 @@ xf86RandR12ScreenSetSize (ScreenPtr	pScreen,
     xf86CrtcConfigPtr	config = XF86_CRTC_CONFIG_PTR(pScrn);
     WindowPtr		pRoot = pScreen->root;
     PixmapPtr		pScrnPix;
+    Bool                panning = FALSE;
     Bool		ret = FALSE;
     int                 c;
 
@@ -708,8 +715,7 @@ xf86RandR12ScreenSetSize (ScreenPtr	pScreen,
     /* Update panning information */
     for (c = 0; c < config->num_crtc; c++) {
 	xf86CrtcPtr crtc = config->crtc[c];
-	if (crtc->panningTotalArea.x2 > crtc->panningTotalArea.x1 ||
-	    crtc->panningTotalArea.y2 > crtc->panningTotalArea.y1) {
+	if (PANNING_ENABLED (crtc)) {
 	    if (crtc->panningTotalArea.x2 > crtc->panningTrackingArea.x1)
 		crtc->panningTotalArea.x2 += width  - pScreen->width;
 	    if (crtc->panningTotalArea.y2 > crtc->panningTrackingArea.y1)
@@ -720,9 +726,12 @@ xf86RandR12ScreenSetSize (ScreenPtr	pScreen,
 		crtc->panningTrackingArea.y2 += height - pScreen->height;
 	    xf86RandR13VerifyPanningArea (crtc, width, height);
 	    xf86RandR13Pan (crtc, randrp->pointerX, randrp->pointerY);
+            panning = TRUE;
 	}
     }
 
+    randrp->panning = panning;
+
     pScrnPix = (*pScreen->GetScreenPixmap)(pScreen);
     pScreen->width = pScrnPix->drawable.width = width;
     pScreen->height = pScrnPix->drawable.height = height;
@@ -925,6 +934,7 @@ xf86RandR12CloseScreen (ScreenPtr pScreen)
     randrp = XF86RANDRINFO(pScreen);
 #if RANDR_12_INTERFACE
     xf86Screens[pScreen->myNum]->EnterVT = randrp->orig_EnterVT;
+    pScreen->ConstrainCursorHarder = randrp->orig_ConstrainCursorHarder;
 #endif
 
     free(randrp);
@@ -1226,6 +1236,7 @@ xf86RandR12CrtcSet (ScreenPtr	    pScreen,
 	    }
 	    xf86RandR13VerifyPanningArea (crtc, pScreen->width, pScreen->height);
 	    xf86RandR13Pan (crtc, randrp->pointerX, randrp->pointerY);
+            randrp->panning = PANNING_ENABLED (crtc);
 	    /*
 	     * Save the last successful setting for EnterVT
 	     */
@@ -1650,6 +1661,7 @@ xf86RandR13SetPanning (ScreenPtr           pScreen,
 {
     XF86RandRInfoPtr	randrp  = XF86RANDRINFO(pScreen);
     xf86CrtcPtr		crtc = randr_crtc->devPrivate;
+    Bool                oldPanning = randrp->panning;
     BoxRec		oldTotalArea;
     BoxRec		oldTrackingArea;
     INT16		oldBorder[4];
@@ -1671,12 +1683,14 @@ xf86RandR13SetPanning (ScreenPtr           pScreen,
 
     if (xf86RandR13VerifyPanningArea (crtc, pScreen->width, pScreen->height)) {
 	xf86RandR13Pan (crtc, randrp->pointerX, randrp->pointerY);
+        randrp->panning = PANNING_ENABLED (crtc);
 	return TRUE;
     } else {
 	/* Restore old settings */
 	memcpy (&crtc->panningTotalArea,    &oldTotalArea,    sizeof(BoxRec));
 	memcpy (&crtc->panningTrackingArea, &oldTrackingArea, sizeof(BoxRec));
 	memcpy (crtc->panningBorder,         oldBorder,       4*sizeof(INT16));
+        randrp->panning = oldPanning;
 	return FALSE;
     }
 }
@@ -1761,6 +1775,21 @@ xf86RandR12EnterVT (int screen_index, int flags)
     return RRGetInfo (pScreen, TRUE); /* force a re-probe of outputs and notify clients about changes */
 }
 
+static void
+xf86RandR13ConstrainCursorHarder(DeviceIntPtr dev, ScreenPtr screen, int mode, int *x, int *y)
+{
+    XF86RandRInfoPtr randrp = XF86RANDRINFO(screen);
+
+    if (randrp->panning)
+        return;
+
+    if (randrp->orig_ConstrainCursorHarder) {
+        screen->ConstrainCursorHarder = randrp->orig_ConstrainCursorHarder;
+        screen->ConstrainCursorHarder(dev, screen, mode, x, y);
+        screen->ConstrainCursorHarder = xf86RandR13ConstrainCursorHarder;
+    }
+}
+
 static Bool
 xf86RandR12Init12 (ScreenPtr pScreen)
 {
@@ -1789,6 +1818,10 @@ xf86RandR12Init12 (ScreenPtr pScreen)
     randrp->orig_EnterVT = pScrn->EnterVT;
     pScrn->EnterVT = xf86RandR12EnterVT;
 
+    randrp->panning = FALSE;
+    randrp->orig_ConstrainCursorHarder = pScreen->ConstrainCursorHarder;
+    pScreen->ConstrainCursorHarder = xf86RandR13ConstrainCursorHarder;
+
     if (!xf86RandR12CreateObjects12 (pScreen))
 	return FALSE;
 
-- 
1.7.6