Abstract cursor refcounting

Too many callers relied on the refcnt being handled correctly. Use a simple
wrapper to handle that case.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit 9a5ad65330693b3273972b63d10f2907d9ab954a)

4 files changed, 45 insertions, 31 deletions

diff --git a/dix/cursor.c b/dix/cursor.c
index 1ee127ac5..0820b18ad 100644
--- a/dix/cursor.c
+++ b/dix/cursor.c
@@ -114,9 +114,13 @@ FreeCursor(pointer value, XID cid)
     ScreenPtr pscr;
     DeviceIntPtr pDev = NULL;   /* unused anyway */
 
-    if (--pCurs->refcnt != 0)
+
+    UnrefCursor(pCurs);
+    if (CursorRefCount(pCurs) != 0)
         return Success;
 
+    BUG_WARN(CursorRefCount(pCurs) < 0);
+
     for (nscr = 0; nscr < screenInfo.numScreens; nscr++) {
         pscr = screenInfo.screens[nscr];
         (void) (*pscr->UnrealizeCursor) (pDev, pscr, pCurs);
@@ -127,6 +131,33 @@ FreeCursor(pointer value, XID cid)
     return Success;
 }
 
+CursorPtr
+RefCursor(CursorPtr cursor)
+{
+    ErrorF("%s ::::: cursor is %p", __func__, cursor);
+    if (cursor) {
+        xorg_backtrace();
+        cursor->refcnt++;
+    }
+    ErrorF("\n");
+    return cursor;
+}
+
+CursorPtr
+UnrefCursor(CursorPtr cursor)
+{
+    if (cursor)
+        cursor->refcnt--;
+    return cursor;
+}
+
+int
+CursorRefCount(const CursorPtr cursor)
+{
+    return cursor ? cursor->refcnt : 0;
+}
+
+
 /*
  * We check for empty cursors so that we won't have to display them
  */
diff --git a/dix/events.c b/dix/events.c
index 64a8f15ed..4d50a2471 100644
--- a/dix/events.c
+++ b/dix/events.c
@@ -931,8 +931,7 @@ ChangeToCursor(DeviceIntPtr pDev, CursorPtr cursor)
 
         (*pScreen->DisplayCursor) (pDev, pScreen, cursor);
         FreeCursor(pSprite->current, (Cursor) 0);
-        pSprite->current = cursor;
-        pSprite->current->refcnt++;
+        pSprite->current = RefCursor(cursor);
     }
 }
 
@@ -3207,11 +3206,10 @@ InitializeSprite(DeviceIntPtr pDev, WindowPtr pWin)
         pSprite->pEnqueueScreen = screenInfo.screens[0];
         pSprite->pDequeueScreen = pSprite->pEnqueueScreen;
     }
-    if (pCursor)
-        pCursor->refcnt++;
+    pCursor = RefCursor(pCursor);
     if (pSprite->current)
         FreeCursor(pSprite->current, None);
-    pSprite->current = pCursor;
+    pSprite->current = RefCursor(pCursor);
 
     if (pScreen) {
         (*pScreen->RealizeCursor) (pDev, pScreen, pSprite->current);
@@ -3290,9 +3288,7 @@ UpdateSpriteForScreen(DeviceIntPtr pDev, ScreenPtr pScreen)
     pSprite->hotLimits.x2 = pScreen->width;
     pSprite->hotLimits.y2 = pScreen->height;
     pSprite->win = win;
-    pCursor = wCursor(win);
-    if (pCursor)
-        pCursor->refcnt++;
+    pCursor = RefCursor(wCursor(win));
     if (pSprite->current)
         FreeCursor(pSprite->current, 0);
     pSprite->current = pCursor;
@@ -4942,9 +4938,7 @@ ProcChangeActivePointerGrab(ClientPtr client)
         (CompareTimeStamps(time, device->deviceGrab.grabTime) == EARLIER))
         return Success;
     oldCursor = grab->cursor;
-    grab->cursor = newCursor;
-    if (newCursor)
-        newCursor->refcnt++;
+    grab->cursor = RefCursor(newCursor);
     PostNewCursor(device);
     if (oldCursor)
         FreeCursor(oldCursor, (Cursor) 0);
@@ -5089,9 +5083,7 @@ GrabDevice(ClientPtr client, DeviceIntPtr dev,
         else
             xi2mask_merge(tempGrab->xi2mask, mask->xi2mask);
         tempGrab->device = dev;
-        tempGrab->cursor = cursor;
-        if (cursor)
-            tempGrab->cursor->refcnt++;
+        tempGrab->cursor = RefCursor(cursor);
         tempGrab->confineTo = confineTo;
         tempGrab->grabtype = grabtype;
         (*grabInfo->ActivateGrab) (dev, tempGrab, time, FALSE);
diff --git a/dix/grabs.c b/dix/grabs.c
index b254ddcf1..a03897af4 100644
--- a/dix/grabs.c
+++ b/dix/grabs.c
@@ -241,13 +241,11 @@ CreateGrab(int client, DeviceIntPtr device, DeviceIntPtr modDevice,
     grab->detail.exact = keybut;
     grab->detail.pMask = NULL;
     grab->confineTo = confineTo;
-    grab->cursor = cursor;
+    grab->cursor = RefCursor(cursor);
     grab->next = NULL;
 
     if (grabtype == XI2)
         xi2mask_merge(grab->xi2mask, mask->xi2mask);
-    if (cursor)
-        cursor->refcnt++;
     return grab;
 
 }
@@ -274,9 +272,6 @@ CopyGrab(GrabPtr dst, const GrabPtr src)
     Mask *details_mask = NULL;
     XI2Mask *xi2mask;
 
-    if (src->cursor)
-        src->cursor->refcnt++;
-
     if (src->modifiersDetail.pMask) {
         int len = MasksPerDetailMask * sizeof(Mask);
 
@@ -314,6 +309,7 @@ CopyGrab(GrabPtr dst, const GrabPtr src)
     dst->modifiersDetail.pMask = mdetails_mask;
     dst->detail.pMask = details_mask;
     dst->xi2mask = xi2mask;
+    dst->cursor = RefCursor(src->cursor);
 
     xi2mask_merge(dst->xi2mask, src->xi2mask);
 
diff --git a/dix/window.c b/dix/window.c
index a5b28a630..8e61779e7 100644
--- a/dix/window.c
+++ b/dix/window.c
@@ -547,8 +547,7 @@ InitRootWindow(WindowPtr pWin)
     (*pScreen->PositionWindow) (pWin, 0, 0);
 
     pWin->cursorIsNone = FALSE;
-    pWin->optional->cursor = rootCursor;
-    rootCursor->refcnt++;
+    pWin->optional->cursor = RefCursor(rootCursor);
 
     if (party_like_its_1989) {
         MakeRootTile(pWin);
@@ -1416,8 +1415,7 @@ ChangeWindowAttributes(WindowPtr pWin, Mask vmask, XID *vlist, ClientPtr client)
                     else if (pWin->parent && pCursor == wCursor(pWin->parent))
                         checkOptional = TRUE;
                     pOldCursor = pWin->optional->cursor;
-                    pWin->optional->cursor = pCursor;
-                    pCursor->refcnt++;
+                    pWin->optional->cursor = RefCursor(pCursor);
                     pWin->cursorIsNone = FALSE;
                     /*
                      * check on any children now matching the new cursor
@@ -3321,8 +3319,7 @@ MakeWindowOptional(WindowPtr pWin)
     parentOptional = FindWindowWithOptional(pWin)->optional;
     optional->visual = parentOptional->visual;
     if (!pWin->cursorIsNone) {
-        optional->cursor = parentOptional->cursor;
-        optional->cursor->refcnt++;
+        optional->cursor = RefCursor(parentOptional->cursor);
     }
     else {
         optional->cursor = None;
@@ -3410,8 +3407,7 @@ ChangeWindowDeviceCursor(WindowPtr pWin, DeviceIntPtr pDev, CursorPtr pCursor)
     if (pCursor && WindowParentHasDeviceCursor(pWin, pDev, pCursor))
         pNode->cursor = None;
     else {
-        pNode->cursor = pCursor;
-        pCursor->refcnt++;
+        pNode->cursor = RefCursor(pCursor);
     }
 
     pNode = pPrev = NULL;
@@ -3419,8 +3415,7 @@ ChangeWindowDeviceCursor(WindowPtr pWin, DeviceIntPtr pDev, CursorPtr pCursor)
     for (pChild = pWin->firstChild; pChild; pChild = pChild->nextSib) {
         if (WindowSeekDeviceCursor(pChild, pDev, &pNode, &pPrev)) {
             if (pNode->cursor == None) {        /* inherited from parent */
-                pNode->cursor = pOldCursor;
-                pOldCursor->refcnt++;
+                pNode->cursor = RefCursor(pOldCursor);
             }
             else if (pNode->cursor == pCursor) {
                 pNode->cursor = None;