diff --git a/polymer/eduke32/package/sdk/samples/a.m32 b/polymer/eduke32/package/sdk/samples/a.m32
index 2db596b39..98524326d 100644
--- a/polymer/eduke32/package/sdk/samples/a.m32
+++ b/polymer/eduke32/package/sdk/samples/a.m32
@@ -1563,6 +1563,53 @@ defstate sanitize_underwater_sprites
     printmessage16 "Set xvel=1 on highlighted wall/floor sprites"
 ends
 
+define BZ_MAX 8388608
+
+defstate uniformceil
+    var avgz n
+
+    for i selsectors
+    {
+        ifand sector[i].ceilingstat 2 xor sector[i].ceilingstat 2
+        add avgz sector[i].ceilingz
+        add n 1
+    }
+
+    ife n 0 break
+
+    div avgz n
+    and avgz 0xfffffc00  // round to one PGUP/PNDN unit (1024 z units)
+
+    ifvarge avgz -BZ_MAX ifvarle avgz BZ_MAX nullop
+    else quote "ERROR: average z value outside [-8388608 .. 8388608]"  // BZ_MAX
+
+    for i selsectors
+        set sector[i].ceilingz avgz
+ends
+
+// XXX: CODEDUP
+defstate uniformfloor
+    var avgz n
+
+    for i selsectors
+    {
+        ifand sector[i].floorstat 2 xor sector[i].floorstat 2
+        add avgz sector[i].floorz
+        add n 1
+    }
+
+    ife n 0 break
+
+    div avgz n
+    and avgz 0xfffffc00  // round to one PGUP/PNDN unit (1024 z units)
+
+    ifvarge avgz -BZ_MAX ifvarle avgz BZ_MAX nullop
+    else quote "ERROR: average z value outside [-8388608 .. 8388608]"  // BZ_MAX
+
+    for i selsectors
+        set sector[i].floorz avgz
+ends
+
 // This must be *compiled* with script_expertmode
 /*
 defstate setstartpos
diff --git a/polymer/eduke32/source/m32exec.c b/polymer/eduke32/source/m32exec.c
index 60e1142f0..ed11437cb 100644
--- a/polymer/eduke32/source/m32exec.c
+++ b/polymer/eduke32/source/m32exec.c
@@ -149,7 +149,7 @@ void VM_OnEvent(register int32_t iEventID, register int32_t iActor)
         int32_t localvars[M32_LOCALS_FIXEDNUM];
 #endif
 
-        // needed since any read access before initialization would cause undefined behaviour
+        // Initialize 'state'-local variables to 0.
         if (aEventNumLocals[iEventID] > 0)
             Bmemset(localvars, 0, aEventNumLocals[iEventID]*sizeof(int32_t));