2007-10-21  Paolo Bonzini  <bonzini@gnu.org>

	* Sets.st: Fix all sort of off-by-one errors.
	* iconvtests.st: Add regression tests.

--- orig/packages/iconv/Sets.st
+++ mod/packages/iconv/Sets.st
@@ -996,10 +996,10 @@ Iconv is skipped altogether and only Sma
 	    ifTrue: 
 		[readBuffer 
 		    replaceFrom: 1
-		    to: readEnd - readPos
+		    to: readEnd - readPos + 1
 		    with: readBuffer
 		    startingAt: readPos.
-		readEnd := readEnd - readPos.
+		readEnd := readEnd - readPos + 1.
 		readPos := 1].
 	[readEnd >= self bufferSize or: [self atEndOfInput]] whileFalse: 
 		[readEnd := readEnd + 1.
@@ -1044,7 +1044,7 @@ Iconv is skipped altogether and only Sma
 
     convertMore [
 	<category: 'private - conversion'>
-	| bytesLeft fine |
+	| oldReadPos bytesLeft fine |
 	recodedBuffer isNil ifTrue: [self initBuffers].
 	readBuffer isNil ifTrue: [^true].
 	iconvHandle isNil ifTrue: [self iconvOpen].
@@ -1058,15 +1058,18 @@ Iconv is skipped altogether and only Sma
 		    to: recodedBuffer
 		    size: self bufferSize
 		    state: bytesLeft.
-	readPos := self bufferSize - (bytesLeft at: 1).
+	oldReadPos := readPos.
+	readPos := readEnd + 1 - (bytesLeft at: 1).
 	recodedEnd := self bufferSize - (bytesLeft at: 2).
 	recodedPos := 1.
 	fine ifFalse: [InvalidSequenceError signal. ^true].
+	readPos > readEnd ifFalse: [
+	    readPos = oldReadPos ifTrue: [ IncompleteSequenceError signal ].
+	    ^readPos = oldReadPos ].
 	self atEndOfInput ifFalse: [^false].
 
 	"At end of input, check whether the last character was complete."
 	readBuffer := nil.
-	readPos <= readEnd ifTrue: [IncompleteSequenceError signal. ^true].
 	^recodedEnd = 0
     ]
 ]
--- orig/packages/iconv/iconvtests.st
+++ mod/packages/iconv/iconvtests.st
@@ -180,5 +180,53 @@ TestCase subclass: IconvTest [
 	str := UnicodeString with: $<16r10FFFF>.
 	self assert: (str asString: 'UTF-7') asString = '+2//f/w-'
     ]
+
+    testRoundTrip [
+	<category: 'test'>
+	| s |
+	s := String new: 1 withAll: $x.
+	self assert: (s asUnicodeString asString: 'UTF-8') = s.
+	s := String new: 1024 withAll: $x.
+	self assert: (s asUnicodeString asString: 'UTF-8') = s.
+	s := String new: 1025 withAll: $x.
+	self assert: (s asUnicodeString asString: 'UTF-8') = s.
+	s := UnicodeString new: 1 withAll: $x.
+	self assert: (s asString: 'UTF-8') asUnicodeString = s.
+	s := UnicodeString new: 1024 withAll: $x.
+	self assert: (s asString: 'UTF-8') asUnicodeString = s.
+	s := UnicodeString new: 1025 withAll: $x.
+	self assert: (s asString: 'UTF-8') asUnicodeString = s.
+	s := UnicodeString new: 1025 withAll: $<16r4000>.
+	self assert: (s asString: 'UTF-8') asUnicodeString = s.
+	s := UnicodeString new: 1025 withAll: $<16r4000>.
+	self assert: (s asString: 'UTF-8') asUnicodeString = s
+    ]
+
+    testExceptions [
+	<category: 'test'>
+	| b |
+	self should: [ #[228] asUnicodeString ] raise: IncompleteSequenceError.
+	self should: [ #[128] asUnicodeString ] raise: InvalidSequenceError.
+	self should: [ #[228 128] asUnicodeString ] raise: IncompleteSequenceError.
+
+	"On some OSes we return IncompleteSequenceError for the following."
+	"self should: [ #[228 228] asUnicodeString ] raise: InvalidSequenceError."
+
+	b := ByteArray new: 1026.
+	b atAll: (1 to: 1026 by: 3) put: 228.
+	b atAll: (2 to: 1026 by: 3) put: 128.
+	b atAll: (3 to: 1026 by: 3) put: 128.
+	self shouldnt: [ b asUnicodeString ] raise: IncompleteSequenceError.
+
+	b := b copyFrom: 1 to: 1025.
+	self should: [ b asUnicodeString ] raise: IncompleteSequenceError.
+
+	b at: 1025 put: 228.
+	"On some OSes we return IncompleteSequenceError for the following."
+	"self should: [ b asUnicodeString ] raise: InvalidSequenceError."
+
+	b := b copyFrom: 1 to: 1024.
+	self should: [ b asUnicodeString ] raise: IncompleteSequenceError.
+    ]
 ]