--- a/BTree.st	Fri Sep 06 01:12:44 2013 +0200
+++ b/BTree.st	Fri Sep 06 01:15:11 2013 +0200
@@ -839,15 +839,15 @@
 !
 
 extractPrefixFrom: readStreams
-	| prefixStream nextChars |
-	prefixStream _ String new writeStream.
-	
-	[readStreams anySatisfy: [:ea | ea atEnd]] whileFalse:
-		[nextChars _ readStreams collect: [:ea | ea next].
-		(nextChars allSatisfy: [:ea | ea = nextChars first])
-				ifTrue: [prefixStream nextPut: nextChars first]
-				ifFalse: [readStreams do: [:ea | ea skip: -1]. ^ prefixStream contents]].
-	^ prefixStream contents
+        | prefixStream nextChars |
+        prefixStream _ String new writeStream.
+        
+        [readStreams anySatisfy: [:ea | ea atEnd]] whileFalse:
+                [nextChars _ readStreams collect: [:ea | ea next].
+                (nextChars conform: [:ea | ea = nextChars first])
+                                ifTrue: [prefixStream nextPut: nextChars first]
+                                ifFalse: [readStreams do: [:ea | ea skip: -1]. ^ prefixStream contents]].
+        ^ prefixStream contents
 !
 
 findIndexForKey: aString
@@ -894,6 +894,6 @@
 !BTree class methodsFor:'documentation'!
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic2/BTree.st,v 1.14 2013-07-08 13:05:21 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/BTree.st,v 1.15 2013-09-05 23:15:11 cg Exp $'
 ! !