--- a/Tools__Diff3CodeView2.st	Fri Mar 16 22:44:50 2012 +0000
+++ b/Tools__Diff3CodeView2.st	Fri Mar 16 23:23:39 2012 +0000
@@ -180,11 +180,17 @@
 !Diff3CodeView2::Diff3Data methodsFor:'computing'!
 
 addLines: total from: src to: dst offset: offset length: len
+    | start stop |
 
-    offset to: offset + len - 1 do:[:i|
-        dst add: (src at: i).
+    start := offset min: src size.
+    stop  := (offset + len - 1) min: src size.
+
+    start < stop ifTrue:[
+        start to: stop do:[:i|
+            dst add: (src at: i).
+        ].
     ].
-    (total - len) timesRepeat: [ dst add: nil ].
+    (total - (stop - start + 1)) timesRepeat: [ dst add: nil ].
 
     "Created: / 16-03-2012 / 22:20:22 / Jan Vrany <jan.vrany@fit.cvut.cz>"
 !
@@ -192,15 +198,22 @@
 computeDiffDataForText1:t1 text2:t2 text3: t3
     | t1c t2c  t3c  diff3chunks lnr |
 
-    t1c := (text1 := t1) asStringCollection.
-    t2c := (text2 := t2) asStringCollection.
-    t3c := (text3 := t3) asStringCollection.
     list1 := StringCollection new.
     list2 := StringCollection new.
     list3 := StringCollection new.
     changed := OrderedCollection new.
     inserted2 := OrderedCollection new.
     inserted3 := OrderedCollection new.
+
+    t1 isNil ifTrue:[ ^self ].
+    t2 isNil ifTrue:[ ^self ].
+    t3 isNil ifTrue:[ ^self ].
+
+
+    t1c := (text1 := t1) asStringCollection.
+    t2c := (text2 := t2) asStringCollection.
+    t3c := (text3 := t3) asStringCollection.
+
     
     diff3chunks := Diff3 new
                     file0: t1c; "/Base version
@@ -225,16 +238,16 @@
                 self addLines: len from: t1c to: list3 offset: chunk offset length: len.
             ].
             chunk side == #left ifTrue:[
-                self addLines: len from: t1c to: list1 offset: chunk offset length: 0.
+                self addLines: len from: t1c to: list1 offset: chunk offset length: len.
                 self addLines: len from: t2c to: list2 offset: chunk offset length: len.
-                self addLines: len from: t3c to: list3 offset: chunk offset length: 0.
-                lnr to:(lnr + len -1) do:[:i|inserted2 add: i].
+                self addLines: len from: t3c to: list3 offset: chunk offset length: len.
+                lnr to:(lnr + len - 1) do:[:i| changed add:i ].
             ].
             chunk side == #right ifTrue:[
-                self addLines: len from: t1c to: list1 offset: chunk offset length: 0.
-                self addLines: len from: t2c to: list2 offset: chunk offset length: 0.
+                self addLines: len from: t1c to: list1 offset: chunk offset length: len.
+                self addLines: len from: t2c to: list2 offset: chunk offset length: len.
                 self addLines: len from: t3c to: list3 offset: chunk offset length: len.
-                lnr to:(lnr + len -1) do:[:i|inserted3 add: i].
+                lnr to:(lnr + len - 1) do:[:i|changed add: i].
             ]
         ].
         lnr := lnr + len.
@@ -246,5 +259,5 @@
 !Diff3CodeView2 class methodsFor:'documentation'!
 
 version_SVN
-    ^ '$Id: Tools__Diff3CodeView2.st 7936 2012-03-16 22:44:50Z vranyj1 $'
+    ^ '$Id: Tools__Diff3CodeView2.st 7937 2012-03-16 23:23:39Z vranyj1 $'
 ! !