randr: Avoid re-querying the configuration on everything but GetScreenResources.

The new path should only re-query on the other requests when we haven't
gathered the information from the DDX yet (such as with a non-RandR 1.2 DDX).

Bug #19037.
(cherry picked from commit 317f2b4a9fe4b606975711bc332166a82db5087d)

4 files changed, 16 insertions, 12 deletions

diff --git a/randr/randrstr.h b/randr/randrstr.h
index b5cebdc7e..9c9b7c074 100644
--- a/randr/randrstr.h
+++ b/randr/randrstr.h
@@ -468,7 +468,7 @@ RRTellChanged (ScreenPtr pScreen);
  * Poll the driver for changed information
  */
 Bool
-RRGetInfo (ScreenPtr pScreen);
+RRGetInfo (ScreenPtr pScreen, Bool force_query);
 
 Bool RRInit (void);
 
diff --git a/randr/rrinfo.c b/randr/rrinfo.c
index 38314defd..12b9a4aab 100644
--- a/randr/rrinfo.c
+++ b/randr/rrinfo.c
@@ -178,12 +178,20 @@ RRScanOldConfig (ScreenPtr pScreen, Rotation rotations)
  * Poll the driver for changed information
  */
 Bool
-RRGetInfo (ScreenPtr pScreen)
+RRGetInfo (ScreenPtr pScreen, Bool force_query)
 {
     rrScrPriv (pScreen);
     Rotation	    rotations;
     int		    i;
 
+    /* Return immediately if we don't need to re-query and we already have the
+     * information.
+     */
+    if (!force_query) {
+	if (pScrPriv->numCrtcs != 0 || pScrPriv->numOutputs != 0)
+	    return TRUE;
+    }
+
     for (i = 0; i < pScrPriv->numOutputs; i++)
 	pScrPriv->outputs[i]->changed = FALSE;
     for (i = 0; i < pScrPriv->numCrtcs; i++)
diff --git a/randr/rrscreen.c b/randr/rrscreen.c
index 95662c9a9..da633b237 100644
--- a/randr/rrscreen.c
+++ b/randr/rrscreen.c
@@ -224,7 +224,7 @@ ProcRRGetScreenSizeRange (ClientPtr client)
     
     if (pScrPriv) 
     {
-	if (!RRGetInfo (pScreen))
+	if (!RRGetInfo (pScreen, FALSE))
 	    return BadAlloc;
 	rep.minWidth  = pScrPriv->minWidth;
 	rep.minHeight = pScrPriv->minHeight;
@@ -340,7 +340,7 @@ rrGetScreenResources(ClientPtr client, Bool query)
     rep.pad = 0;
     
     if (query && pScrPriv)
-	if (!RRGetInfo (pScreen))
+	if (!RRGetInfo (pScreen, query))
 	    return BadAlloc;
 
     if (!pScrPriv)
@@ -615,7 +615,7 @@ ProcRRGetScreenInfo (ClientPtr client)
     rep.pad = 0;
     
     if (pScrPriv)
-	if (!RRGetInfo (pScreen))
+	if (!RRGetInfo (pScreen, FALSE))
 	    return BadAlloc;
 
     output = RRFirstOutput (pScreen);
@@ -796,7 +796,7 @@ ProcRRSetScreenConfig (ClientPtr client)
 	rep.status = RRSetConfigFailed;
 	goto sendReply;
     }
-    if (!RRGetInfo (pScreen))
+    if (!RRGetInfo (pScreen, FALSE))
 	return BadAlloc;
     
     output = RRFirstOutput (pScreen);
diff --git a/randr/rrxinerama.c b/randr/rrxinerama.c
index 7f9a79827..36135c6c1 100644
--- a/randr/rrxinerama.c
+++ b/randr/rrxinerama.c
@@ -307,12 +307,8 @@ ProcRRXineramaQueryScreens(ClientPtr client)
     REQUEST_SIZE_MATCH(xXineramaQueryScreensReq);
 
     if (RRXineramaScreenActive (pScreen))
-    {
-	rrScrPriv(pScreen);
-	if (pScrPriv->numCrtcs == 0 || pScrPriv->numOutputs == 0)
-	    RRGetInfo (pScreen);
-    }
-    
+	RRGetInfo (pScreen, FALSE);
+
     rep.type = X_Reply;
     rep.sequenceNumber = client->sequence;
     rep.number = RRXineramaScreenCount (pScreen);