diff --git a/configure.ac b/configure.ac
index 89a7a9db9..75281f001 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2003,7 +2003,7 @@ AM_CONDITIONAL(STANDALONE_XPBPROXY, [test "x$STANDALONE_XPBPROXY" = xyes])
 dnl DMX DDX
 PKG_CHECK_MODULES(
 	[DMXMODULES],
-	[xmuu $LIBXEXT x11 xrender xfixes $LIBXI $DMXPROTO xau $XDMCP_MODULES],
+	[xmuu $LIBXEXT x11 >= 1.6 xrender xfixes $LIBXI $DMXPROTO xau $XDMCP_MODULES],
 	[PKG_CHECK_MODULES(
 		[XDMXCONFIG_DEP],
 		[xaw7 xmu xt xpm x11],
@@ -2112,7 +2112,7 @@ if test "$KDRIVE" = yes; then
        AC_DEFINE(KDRIVE_MOUSE, 1, [Enable KDrive mouse driver])
     fi
 
-    XEPHYR_REQUIRED_LIBS="x11 $LIBXEXT xau xdmcp"
+    XEPHYR_REQUIRED_LIBS="x11 >= 1.6 $LIBXEXT xau xdmcp"
     if test "x$XV" = xyes; then
         XEPHYR_REQUIRED_LIBS="$XEPHYR_REQUIRED_LIBS xv"
     fi
diff --git a/hw/dmx/dmx_glxvisuals.c b/hw/dmx/dmx_glxvisuals.c
index f903b7491..56bd67b6e 100644
--- a/hw/dmx/dmx_glxvisuals.c
+++ b/hw/dmx/dmx_glxvisuals.c
@@ -37,6 +37,7 @@
 #include <GL/glxproto.h>
 #include <X11/extensions/Xext.h>
 #include <X11/extensions/extutil.h>
+#include <limits.h>
 
 #include "dmx_glxvisuals.h"
 
@@ -84,7 +85,10 @@ GetGLXVisualConfigs(Display * dpy, int screen, int *nconfigs)
         SyncHandle();
         return NULL;
     }
-    props = (INT32 *) Xmalloc(nprops * __GLX_SIZE_CARD32);
+    if (nprops < (INT_MAX / __GLX_SIZE_CARD32))
+        props = Xmalloc(nprops * __GLX_SIZE_CARD32);
+    else
+        props = NULL;
     if (!props) {
         UnlockDisplay(dpy);
         SyncHandle();
@@ -92,15 +96,16 @@ GetGLXVisualConfigs(Display * dpy, int screen, int *nconfigs)
     }
 
     /* Allocate memory for our config structure */
-    config = (__GLXvisualConfig *)
-        Xmalloc(nvisuals * sizeof(__GLXvisualConfig));
+    if (nvisuals < (INT_MAX / sizeof(__GLXvisualConfig)))
+        config = Xcalloc(nvisuals, sizeof(__GLXvisualConfig));
+    else
+        config = NULL;
     if (!config) {
         free(props);
         UnlockDisplay(dpy);
         SyncHandle();
         return NULL;
     }
-    memset(config, 0, nvisuals * sizeof(__GLXvisualConfig));
     configs = config;
     num_good_visuals = 0;
 
@@ -274,7 +279,10 @@ GetGLXFBConfigs(Display * dpy, int glxMajorOpcode, int *nconfigs)
         return NULL;
     }
 
-    attrs = (INT32 *) Xmalloc(2 * numAttribs * __GLX_SIZE_CARD32);
+    if (numAttribs < (INT_MAX / (2 * __GLX_SIZE_CARD32)))
+        attrs = Xmalloc(2 * numAttribs * __GLX_SIZE_CARD32);
+    else
+        attrs = NULL;
     if (!attrs) {
         UnlockDisplay(dpy);
         SyncHandle();
@@ -282,15 +290,16 @@ GetGLXFBConfigs(Display * dpy, int glxMajorOpcode, int *nconfigs)
     }
 
     /* Allocate memory for our config structure */
-    config = (__GLXFBConfig *)
-        Xmalloc(numFBConfigs * sizeof(__GLXFBConfig));
+    if (numFBConfigs < (INT_MAX / sizeof(__GLXFBConfig)))
+        config = Xcalloc(numFBConfigs, sizeof(__GLXFBConfig));
+    else
+        config = NULL;
     if (!config) {
         free(attrs);
         UnlockDisplay(dpy);
         SyncHandle();
         return NULL;
     }
-    memset(config, 0, numFBConfigs * sizeof(__GLXFBConfig));
     fbconfigs = config;
 
     /* Convert attribute list into our format */
diff --git a/hw/dmx/glxProxy/glxcmds.c b/hw/dmx/glxProxy/glxcmds.c
index 45382748f..8cdb25ec6 100644
--- a/hw/dmx/glxProxy/glxcmds.c
+++ b/hw/dmx/glxProxy/glxcmds.c
@@ -2582,7 +2582,6 @@ __glXQueryExtensionsString(__GLXclientState * cl, GLbyte * pc)
     xGLXQueryExtensionsStringReply be_reply;
     DMXScreenInfo *dmxScreen;
     Display *dpy;
-    int slop;
 #endif
 
     screen = req->screen;
@@ -2608,16 +2607,13 @@ __glXQueryExtensionsString(__GLXclientState * cl, GLbyte * pc)
     _XReply(dpy, (xReply *) &be_reply, 0, False);
     len = (int) be_reply.length;
     numbytes = (int) be_reply.n;
-    slop = numbytes * __GLX_SIZE_INT8 & 3;
     be_buf = (char *) malloc(numbytes);
     if (!be_buf) {
         /* Throw data on the floor */
-        _XEatData(dpy, len);
+        _XEatDataWords(dpy, len);
     }
     else {
-        _XRead(dpy, (char *) be_buf, numbytes);
-        if (slop)
-            _XEatData(dpy, 4 - slop);
+        _XReadPad(dpy, (char *) be_buf, numbytes);
     }
     UnlockDisplay(dpy);
     SyncHandle();
@@ -2666,7 +2662,6 @@ __glXQueryServerString(__GLXclientState * cl, GLbyte * pc)
     xGLXQueryServerStringReply be_reply;
     DMXScreenInfo *dmxScreen;
     Display *dpy;
-    int slop;
 #endif
 
     name = req->name;
@@ -2693,16 +2688,13 @@ __glXQueryServerString(__GLXclientState * cl, GLbyte * pc)
     _XReply(dpy, (xReply *) &be_reply, 0, False);
     len = (int) be_reply.length;
     numbytes = (int) be_reply.n;
-    slop = numbytes * __GLX_SIZE_INT8 & 3;
     be_buf = (char *) malloc(numbytes);
     if (!be_buf) {
         /* Throw data on the floor */
-        _XEatData(dpy, len);
+        _XEatDataWords(dpy, len);
     }
     else {
-        _XRead(dpy, (char *) be_buf, numbytes);
-        if (slop)
-            _XEatData(dpy, 4 - slop);
+        _XReadPad(dpy, (char *) be_buf, numbytes);
     }
     UnlockDisplay(dpy);
     SyncHandle();
diff --git a/hw/dmx/glxProxy/glxscreens.c b/hw/dmx/glxProxy/glxscreens.c
index 2a1909244..138afedf2 100644
--- a/hw/dmx/glxProxy/glxscreens.c
+++ b/hw/dmx/glxProxy/glxscreens.c
@@ -138,7 +138,7 @@ CalcServerVersionAndExtensions(void)
         Display *dpy = dmxScreen->beDisplay;
         xGLXQueryServerStringReq *req;
         xGLXQueryServerStringReply reply;
-        int length, numbytes, slop;
+        int length, numbytes;
 
         /* Send the glXQueryServerString request */
         LockDisplay(dpy);
@@ -151,16 +151,13 @@ CalcServerVersionAndExtensions(void)
 
         length = (int) reply.length;
         numbytes = (int) reply.n;
-        slop = numbytes * __GLX_SIZE_INT8 & 3;
         be_extensions[s] = (char *) malloc(numbytes);
         if (!be_extensions[s]) {
             /* Throw data on the floor */
-            _XEatData(dpy, length);
+            _XEatDataWords(dpy, length);
         }
         else {
-            _XRead(dpy, (char *) be_extensions[s], numbytes);
-            if (slop)
-                _XEatData(dpy, 4 - slop);
+            _XReadPad(dpy, (char *) be_extensions[s], numbytes);
         }
         UnlockDisplay(dpy);
         SyncHandle();
diff --git a/hw/dmx/glxProxy/glxsingle.c b/hw/dmx/glxProxy/glxsingle.c
index e60cfeb70..abfb880a3 100644
--- a/hw/dmx/glxProxy/glxsingle.c
+++ b/hw/dmx/glxProxy/glxsingle.c
@@ -258,7 +258,7 @@ __glXForwardPipe0WithReply(__GLXclientState * cl, GLbyte * pc)
         }
         else {
             /* Throw data on the floor */
-            _XEatData(dpy, be_buf_size);
+            _XEatDataWords(dpy, be_reply.length);
             return BadAlloc;
         }
     }
@@ -357,7 +357,7 @@ __glXForwardAllWithReply(__GLXclientState * cl, GLbyte * pc)
             }
             else {
                 /* Throw data on the floor */
-                _XEatData(dpy, be_buf_size);
+                _XEatDataWords(dpy, be_reply.length);
                 return BadAlloc;
             }
         }
@@ -993,7 +993,7 @@ __glXDisp_ReadPixels(__GLXclientState * cl, GLbyte * pc)
                     }
                     else {
                         /* Throw data on the floor */
-                        _XEatData(dpy, be_buf_size);
+                        _XEatDataWords(dpy, be_reply.length);
                         free(buf);
                         return BadAlloc;
                     }
diff --git a/hw/dmx/glxProxy/glxvendor.c b/hw/dmx/glxProxy/glxvendor.c
index 5777c6acc..50d505c4b 100644
--- a/hw/dmx/glxProxy/glxvendor.c
+++ b/hw/dmx/glxProxy/glxvendor.c
@@ -246,7 +246,7 @@ __glXVForwardPipe0WithReply(__GLXclientState * cl, GLbyte * pc)
         }
         else {
             /* Throw data on the floor */
-            _XEatData(dpy, be_buf_size);
+            _XEatDataWords(dpy, be_reply.length);
             return BadAlloc;
         }
     }
@@ -340,7 +340,7 @@ __glXVForwardAllWithReply(__GLXclientState * cl, GLbyte * pc)
             }
             else {
                 /* Throw data on the floor */
-                _XEatData(dpy, be_buf_size);
+                _XEatDataWords(dpy, be_reply.length);
                 return BadAlloc;
             }
         }
diff --git a/hw/kdrive/ephyr/XF86dri.c b/hw/kdrive/ephyr/XF86dri.c
index 9d742f394..15b62191f 100644
--- a/hw/kdrive/ephyr/XF86dri.c
+++ b/hw/kdrive/ephyr/XF86dri.c
@@ -64,6 +64,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <GL/glx.h>
 #include "xf86dri.h"
 #include <X11/dri/xf86driproto.h>
+#include <limits.h>
 
 static XExtensionInfo _xf86dri_info_data;
 static XExtensionInfo *xf86dri_info = &_xf86dri_info_data;
@@ -225,8 +226,12 @@ XF86DRIOpenConnection(Display * dpy, int screen,
     }
 
     if (rep.length) {
-        if (!(*busIdString = (char *) calloc(rep.busIdStringLength + 1, 1))) {
-            _XEatData(dpy, ((rep.busIdStringLength + 3) & ~3));
+        if (rep.busIdStringLength < INT_MAX)
+            *busIdString = calloc(rep.busIdStringLength + 1, 1);
+        else
+            *busIdString = NULL;
+        if (*busIdString == NULL) {
+            _XEatDataWords(dpy, rep.length);
             UnlockDisplay(dpy);
             SyncHandle();
             TRACE("OpenConnection... return False");
@@ -323,10 +328,12 @@ XF86DRIGetClientDriverName(Display * dpy, int screen,
     *ddxDriverPatchVersion = rep.ddxDriverPatchVersion;
 
     if (rep.length) {
-        if (!
-            (*clientDriverName =
-             (char *) calloc(rep.clientDriverNameLength + 1, 1))) {
-            _XEatData(dpy, ((rep.clientDriverNameLength + 3) & ~3));
+        if (rep.clientDriverNameLength < INT_MAX)
+            *clientDriverName = calloc(rep.clientDriverNameLength + 1, 1);
+        else
+            *clientDriverName = NULL;
+        if (*clientDriverName == NULL) {
+            _XEatDataWords(dpy, rep.length);
             UnlockDisplay(dpy);
             SyncHandle();
             TRACE("GetClientDriverName... return False");
@@ -532,7 +539,7 @@ XF86DRIGetDrawableInfo(Display * dpy, int screen, Drawable drawable,
                           SIZEOF(xGenericReply) +
                           total_rects * sizeof(drm_clip_rect_t)) +
                          3) & ~3) >> 2)) {
-        _XEatData(dpy, rep.length);
+        _XEatDataWords(dpy, rep.length);
         UnlockDisplay(dpy);
         SyncHandle();
         TRACE("GetDrawableInfo... return False");
@@ -606,7 +613,7 @@ XF86DRIGetDeviceInfo(Display * dpy, int screen, drm_handle_t * hFrameBuffer,
 
     if (rep.length) {
         if (!(*pDevPrivate = (void *) calloc(rep.devPrivateSize, 1))) {
-            _XEatData(dpy, ((rep.devPrivateSize + 3) & ~3));
+            _XEatDataWords(dpy, rep.length);
             UnlockDisplay(dpy);
             SyncHandle();
             TRACE("GetDeviceInfo... return False");
diff --git a/hw/kdrive/ephyr/ephyrhostglx.c b/hw/kdrive/ephyr/ephyrhostglx.c
index 5c6c40f0b..6a4392fee 100644
--- a/hw/kdrive/ephyr/ephyrhostglx.c
+++ b/hw/kdrive/ephyr/ephyrhostglx.c
@@ -137,7 +137,7 @@ ephyrHostGLXQueryVersion(int *a_major, int *a_minor)
 }
 
 /**
- * GLX protocol structure for the ficticious "GXLGenericGetString" request.
+ * GLX protocol structure for the ficticious "GLXGenericGetString" request.
  * 
  * This is a non-existant protocol packet.  It just so happens that all of
  * the real protocol packets used to request a string from the server have
@@ -169,7 +169,8 @@ ephyrHostGLXGetStringFromServer(int a_screen_number,
     int default_screen = DefaultScreen(dpy);
     xGLXGenericGetStringReq *req = NULL;
     xGLXSingleReply reply;
-    int length = 0, numbytes = 0, major_opcode = 0, get_string_op = 0;
+    unsigned long length = 0, numbytes = 0;
+    int major_opcode = 0, get_string_op = 0;
 
     EPHYR_RETURN_VAL_IF_FAIL(dpy && a_string, FALSE);
 
@@ -209,36 +210,48 @@ ephyrHostGLXGetStringFromServer(int a_screen_number,
 
     _XReply(dpy, (xReply *) &reply, 0, False);
 
-    length = reply.length * 4;
-    if (!length) {
-        numbytes = 0;
+#if UINT32_MAX >= (ULONG_MAX / 4)
+    if (reply.length >= (ULONG_MAX / 4)) {
+        _XEatDataWords(dpy, reply.length);
+        goto eat_out;
     }
-    else {
+#endif
+    if (reply.length > 0) {
+        length = (unsigned long) reply.length * 4;
         numbytes = reply.size;
+        if (numbytes > length) {
+            EPHYR_LOG_ERROR("string length %d longer than reply length %d\n",
+                            numbytes, length);
+            goto eat_out;
+        }
     }
     EPHYR_LOG("going to get a string of size:%d\n", numbytes);
 
-    *a_string = (char *) Xmalloc(numbytes + 1);
-    if (!a_string) {
+    if (numbytes < INT_MAX)
+        *a_string = Xcalloc(numbytes + 1, 1);
+    else
+        *a_string = NULL;
+    if (*a_string == NULL) {
         EPHYR_LOG_ERROR("allocation failed\n");
-        goto out;
+        goto eat_out;
     }
 
-    memset(*a_string, 0, numbytes + 1);
     if (_XRead(dpy, *a_string, numbytes)) {
-        UnlockDisplay(dpy);
-        SyncHandle();
         EPHYR_LOG_ERROR("read failed\n");
-        goto out;
+        length = 0; /* if read failed, no idea how much to eat */
     }
-    length -= numbytes;
+    else {
+        length -= numbytes;
+        EPHYR_LOG("strname:%#x, strvalue:'%s', strlen:%d\n",
+                  a_string_name, *a_string, numbytes);
+        is_ok = TRUE;
+    }
+
+ eat_out:
     _XEatData(dpy, length);
     UnlockDisplay(dpy);
     SyncHandle();
-    EPHYR_LOG("strname:%#x, strvalue:'%s', strlen:%d\n",
-              a_string_name, *a_string, numbytes);
 
-    is_ok = TRUE;
  out:
     EPHYR_LOG("leave\n");
     return is_ok;
diff --git a/hw/kdrive/ephyr/ephyrhostvideo.c b/hw/kdrive/ephyr/ephyrhostvideo.c
index 362aa055e..05e9ad9f5 100644
--- a/hw/kdrive/ephyr/ephyrhostvideo.c
+++ b/hw/kdrive/ephyr/ephyrhostvideo.c
@@ -677,7 +677,7 @@ ephyrHostXVQueryImageAttributes(int a_port_id,
         _XRead(dpy, (char *) a_offsets, rep.num_planes << 2);
     }
     else {
-        _XEatData(dpy, rep.length << 2);
+        _XEatDataWords(dpy, rep.length);
     }
     *a_width = rep.width;
     *a_height = rep.height;
diff --git a/hw/xnest/Args.h b/hw/xnest/Args.h
index 514a39513..225418d22 100644
--- a/hw/xnest/Args.h
+++ b/hw/xnest/Args.h
@@ -12,7 +12,7 @@ is" without express or implied warranty.
 
 */
 
-#ifndef XNESTARGC_H
+#ifndef XNESTARGS_H
 #define XNESTARGS_H
 
 extern char *xnestDisplayName;