--- a/WriteStream.st	Fri May 13 20:17:32 2016 +0200
+++ b/WriteStream.st	Sat May 14 09:34:43 2016 +0200
@@ -551,38 +551,26 @@
 %{  /* NOCONTEXT */
 
 #ifndef NO_PRIM_STREAM
-    REGISTER int pos;
-    OBJ coll;
-    OBJ p, wL, rL;
-    int __readLimit = -1;
-
-    coll = __INST(collection);
-    p = __INST(position);
+    OBJ coll = __INST(collection);
+    OBJ p = __INST(position);
 
     if (__isNonNilObject(coll) && __isSmallInteger(p) && __isSmallInteger(anObject)) {
-        unsigned ch;
-
-        ch = __intVal(anObject);
+        OBJ wL  = __INST(writeLimit);
+        INT pos = __intVal(p) + 1;    /* make 1-based and usable for update below */
+        unsigned int ch = __intVal(anObject);
 
-        pos = __intVal(p);
-        /* make 1-based and usable for update below */
-        pos = pos + 1;
-        wL = __INST(writeLimit);
+        if (ch <= 0xFF &&  /* ch is unsigned */
+            ((wL == nil) || (__isSmallInteger(wL) && (pos <= __intVal(wL))))) {
+            OBJ cls = __qClass(coll);
+            OBJ rL = __INST(readLimit);
+            INT __readLimit = -1;
 
-        if ((wL == nil)
-         || (__isSmallInteger(wL) && (pos <= __intVal(wL)))) {
-            OBJ cls;
-
-            cls = __qClass(coll);
-
-            rL = __INST(readLimit);
             if (__isSmallInteger(rL)) {
                 __readLimit = __intVal(rL);
             }
 
             if (cls == @global(String)) {
-                if ((pos <= __stringSize(coll))
-                 && (ch <= 0xFF)) { /* ch is unsigned */
+                if (pos <= __stringSize(coll)) { 
                     __StringInstPtr(coll)->s_element[pos-1] = ch;
     advancePositionAndReturn: ;
                     if ((__readLimit >= 0) && (pos > __readLimit)) {
@@ -592,8 +580,7 @@
                     RETURN ( anObject );
                 }
             } else if (cls == @global(ByteArray)) {
-                if ((pos <= __byteArraySize(coll))
-                 && (ch <= 0xFF)) { /* ch is unsigned */
+                if (pos <= __byteArraySize(coll)) { 
                     __ByteArrayInstPtr(coll)->ba_element[pos-1] = ch;
                     goto advancePositionAndReturn;
                 }
@@ -602,7 +589,13 @@
     }
 #endif
 %}.
-    ^ super nextPutByte:anObject
+    ((writeLimit isNil or:[(position + 1) <= writeLimit])
+      and:[position >= collection size]) ifTrue:[
+        self growCollection.
+        ^ self nextPutByte:anObject.  "try again"                    
+    ] ifFalse:[
+        ^ super nextPutByte:anObject
+    ].
 !
 
 nextPutBytes:count from:anObject startingAt:start