dix: add InputEventListLen and SetMinimumEventSize

The latter is used to increase the amount of allocated memory for the event
list. This will be needed for ClassesChangedEvents that can be of more or less
arbitrary size (larger than 32 anyway).

dix/events.c

@@ -5712,7 +5712,8 @@ InitEvents(void)
 	DontPropagateRefCnts[i] = 0;
     }
 
-    InputEventList = InitEventList(GetMaximumEventsNum());
+    InputEventListLen = GetMaximumEventsNum();
+    InputEventList = InitEventList(InputEventListLen);
     if (!InputEventList)
         FatalError("[dix] Failed to allocate input event list.\n");
 }

dix/getevents.c

@@ -75,6 +75,7 @@ extern Bool XkbCopyKeymap(XkbDescPtr src, XkbDescPtr dst, Bool sendNotifies);
  * Get{Pointer|Keyboard}Events.
  */
 EventListPtr InputEventList = NULL;
+int InputEventListLen = 0;
 
 _X_EXPORT EventListPtr
 GetEventList()
@@ -598,6 +599,29 @@ InitEventList(int num_events)
     return events;
 }
 
+/**
+ * Allocs min_size memory for each event in the list.
+ */
+_X_EXPORT void
+SetMinimumEventSize(EventListPtr list, int num_events, int min_size)
+{
+    if (!list)
+        return;
+
+    while(num_events--)
+    {
+        if (list[num_events].evlen < min_size)
+        {
+            list[num_events].event = realloc(list[num_events].event, min_size);
+            if (!list[num_events].event)
+            {
+                FatalError("[dix] Failed to set event list's "
+                        "min_size to %d.\n", min_size);
+            }
+        }
+    }
+}
+
 /**
  * Free an event list.
  *

include/input.h

@@ -96,6 +96,7 @@ typedef struct _EventList {
 
 /* The DIX stores incoming input events in this list */
 extern EventListPtr InputEventList;
+extern int InputEventListLen;
 
 typedef int (*DeviceProc)(
     DeviceIntPtr /*device*/,
@@ -400,6 +401,9 @@ extern int GetMaximumEventsNum(void);
 
 extern EventListPtr GetEventList();
 extern EventListPtr InitEventList(int num_events);
+extern void SetMinimumEventSize(EventListPtr list,
+                                int num_events,
+                                int min_size);
 extern void FreeEventList(EventListPtr list, int num_events);
 
 extern void CreateClassesChangedEvent(EventListPtr event,