<div dir="ltr"><div>Starting to work in my trunk image, I've easily gotten this error a couple of times the last couple of days.  The first was yesterday when I clicked on the "Code" button of an .st file in the File browser.</div><div><br></div><div>This other one, below, was when I dragged a method to a different category, which left the original selected source category empty of any methods...</div><div><br></div><div>Looks like PluggableListMorph>>#visibleList got broken a few weeks ago by making it less defensive.  Reverting it seems to clear up the issue for me, for now...</div><div><br></div><div>Best,</div><div>  Chris</div><div><br></div><div>__________________________________</div>5 November 2019 4:47:14.869338 pm<br><br>VM: unix - Smalltalk<br>Image: Squeak5.3alpha [latest update: #19142]<br><br>SecurityManager state:<br>Restricted: false<br>FileAccess: true<br>SocketAccess: true<br>Working Dir /home/...<br>Trusted Dir /home/...<br>Untrusted Dir /home/...<br><br>Array(Object)>>error:<br>  Receiver: #()<br> Arguments and temporary variables: <br>           aString:        'subscript is out of bounds: 0'<br>       Receiver's instance variables: <br>#()<br><br>Array(Object)>>errorSubscriptBounds:<br>        Receiver: #()<br> Arguments and temporary variables: <br>           index:  0<br>     Receiver's instance variables: <br>#()<br><br>Array(Object)>>at:<br>  Receiver: #()<br> Arguments and temporary variables: <br>           index:  0<br>     Receiver's instance variables: <br>#()<br><br>PluggableListMorphPlus(PluggableListMorph)>>itemAt:<br> Receiver: a PluggableListMorphPlus(2906921)<br>   Arguments and temporary variables: <br>           viewIndex:      0<br>     Receiver's instance variables: <br>           bounds:         933@209 corner: 1171@565<br>              owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      {a TransformMorph(1206197)}<br>           fullBounds:     933@209 corner: 1171@565<br>              color:  Color black<br>           extension:      a MorphExtension (1495327) [other:  (layoutProperties -> a LayoutPro...etc...<br>             borderWidth:    1<br>             borderColor:    (Color r: 0.167 g: 0.22 b: 0.265)<br>             model:  a HierarchyBrowser<br>            slotName:       nil<br>           open:   false<br>         scrollBar:      a ScrollBar(2857491)<br>          scroller:       a TransformMorph(1206197)<br>             retractableScrollBar:   false<br>         scrollBarOnLeft:        false<br>         getMenuSelector:        #messageListMenu:shifted:<br>             getMenuTitleSelector:   nil<br>           hasFocus:       true<br>          hScrollBar:     a ScrollBar(1080941)<br>          hScrollBarPolicy:       #never<br>                vScrollBarPolicy:       #whenNeeded<br>           scrollBarThickness:     10<br>            list:   #()<br>           fullList:       #()<br>           modelToView:    nil<br>           viewToModel:    nil<br>           getListSelector:        #messageList<br>          getListSizeSelector:    nil<br>           getListElementSelector:         nil<br>           getIndexSelector:       #messageListIndex<br>             setIndexSelector:       #messageListIndex:<br>            keystrokeActionSelector:        #messageListKey:from:<br>         autoDeselect:   true<br>          lastKeystrokeTime:      3750446766632<br>         lastKeystrokes:         ''<br>            lastClickTime:  nil<br>           doubleClickSelector:    nil<br>           handlesBasicKeys:       nil<br>           potentialDropRow:       nil<br>           hoverRow:       1<br>             listMorph:      a LazyListMorph(2282769)<br>              keystrokePreviewSelector:       nil<br>           priorSelection:         14<br>            getIconSelector:        #messageIconAt:<br>               getHelpSelector:        #messageHelpAt:<br>               dragItemSelector:       #dragFromMessageList:<br>         dropItemSelector:       nil<br>           wantsDropSelector:      nil<br>           dragTypeSelector:       nil<br>           dragStartedSelector:    nil<br><br>[] in PluggableListMorphPlus(PluggableListMorph)>>visibleList<br>    Receiver: a PluggableListMorphPlus(2906921)<br>   Arguments and temporary variables: <br>           viewIndex:      0<br>     Receiver's instance variables: <br>           bounds:         933@209 corner: 1171@565<br>              owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      {a TransformMorph(1206197)}<br>           fullBounds:     933@209 corner: 1171@565<br>              color:  Color black<br>           extension:      a MorphExtension (1495327) [other:  (layoutProperties -> a LayoutPro...etc...<br>             borderWidth:    1<br>             borderColor:    (Color r: 0.167 g: 0.22 b: 0.265)<br>             model:  a HierarchyBrowser<br>            slotName:       nil<br>           open:   false<br>         scrollBar:      a ScrollBar(2857491)<br>          scroller:       a TransformMorph(1206197)<br>             retractableScrollBar:   false<br>         scrollBarOnLeft:        false<br>         getMenuSelector:        #messageListMenu:shifted:<br>             getMenuTitleSelector:   nil<br>           hasFocus:       true<br>          hScrollBar:     a ScrollBar(1080941)<br>          hScrollBarPolicy:       #never<br>                vScrollBarPolicy:       #whenNeeded<br>           scrollBarThickness:     10<br>            list:   #()<br>           fullList:       #()<br>           modelToView:    nil<br>           viewToModel:    nil<br>           getListSelector:        #messageList<br>          getListSizeSelector:    nil<br>           getListElementSelector:         nil<br>           getIndexSelector:       #messageListIndex<br>             setIndexSelector:       #messageListIndex:<br>            keystrokeActionSelector:        #messageListKey:from:<br>         autoDeselect:   true<br>          lastKeystrokeTime:      3750446766632<br>         lastKeystrokes:         ''<br>            lastClickTime:  nil<br>           doubleClickSelector:    nil<br>           handlesBasicKeys:       nil<br>           potentialDropRow:       nil<br>           hoverRow:       1<br>             listMorph:      a LazyListMorph(2282769)<br>              keystrokePreviewSelector:       nil<br>           priorSelection:         14<br>            getIconSelector:        #messageIconAt:<br>               getHelpSelector:        #messageHelpAt:<br>               dragItemSelector:       #dragFromMessageList:<br>         dropItemSelector:       nil<br>           wantsDropSelector:      nil<br>           dragTypeSelector:       nil<br>           dragStartedSelector:    nil<br><br>Interval>>collect:<br>       Receiver: (0 to: 0)<br>   Arguments and temporary variables: <br>           aBlock:         [closure] in PluggableListMorphPlus(PluggableListMorph)>>visibleList<br>            nextValue:      0<br>             result:         #(nil)<br>                i:      1<br>             iLimiT:         1<br>     Receiver's instance variables: <br>           start:  0<br>             stop:   0<br>             step:   1<br><br>PluggableListMorphPlus(PluggableListMorph)>>visibleList<br>    Receiver: a PluggableListMorphPlus(2906921)<br>   Arguments and temporary variables: <br><br> Receiver's instance variables: <br>           bounds:         933@209 corner: 1171@565<br>              owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      {a TransformMorph(1206197)}<br>           fullBounds:     933@209 corner: 1171@565<br>              color:  Color black<br>           extension:      a MorphExtension (1495327) [other:  (layoutProperties -> a LayoutPro...etc...<br>             borderWidth:    1<br>             borderColor:    (Color r: 0.167 g: 0.22 b: 0.265)<br>             model:  a HierarchyBrowser<br>            slotName:       nil<br>           open:   false<br>         scrollBar:      a ScrollBar(2857491)<br>          scroller:       a TransformMorph(1206197)<br>             retractableScrollBar:   false<br>         scrollBarOnLeft:        false<br>         getMenuSelector:        #messageListMenu:shifted:<br>             getMenuTitleSelector:   nil<br>           hasFocus:       true<br>          hScrollBar:     a ScrollBar(1080941)<br>          hScrollBarPolicy:       #never<br>                vScrollBarPolicy:       #whenNeeded<br>           scrollBarThickness:     10<br>            list:   #()<br>           fullList:       #()<br>           modelToView:    nil<br>           viewToModel:    nil<br>           getListSelector:        #messageList<br>          getListSizeSelector:    nil<br>           getListElementSelector:         nil<br>           getIndexSelector:       #messageListIndex<br>             setIndexSelector:       #messageListIndex:<br>            keystrokeActionSelector:        #messageListKey:from:<br>         autoDeselect:   true<br>          lastKeystrokeTime:      3750446766632<br>         lastKeystrokes:         ''<br>            lastClickTime:  nil<br>           doubleClickSelector:    nil<br>           handlesBasicKeys:       nil<br>           potentialDropRow:       nil<br>           hoverRow:       1<br>             listMorph:      a LazyListMorph(2282769)<br>              keystrokePreviewSelector:       nil<br>           priorSelection:         14<br>            getIconSelector:        #messageIconAt:<br>               getHelpSelector:        #messageHelpAt:<br>               dragItemSelector:       #dragFromMessageList:<br>         dropItemSelector:       nil<br>           wantsDropSelector:      nil<br>           dragTypeSelector:       nil<br>           dragStartedSelector:    nil<br><br>PluggableListMorphPlus(PluggableListMorph)>>charactersOccluded<br>   Receiver: a PluggableListMorphPlus(2906921)<br>   Arguments and temporary variables: <br>           listIndex:      #(0)<br>  Receiver's instance variables: <br>           bounds:         933@209 corner: 1171@565<br>              owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      {a TransformMorph(1206197)}<br>           fullBounds:     933@209 corner: 1171@565<br>              color:  Color black<br>           extension:      a MorphExtension (1495327) [other:  (layoutProperties -> a LayoutPro...etc...<br>             borderWidth:    1<br>             borderColor:    (Color r: 0.167 g: 0.22 b: 0.265)<br>             model:  a HierarchyBrowser<br>            slotName:       nil<br>           open:   false<br>         scrollBar:      a ScrollBar(2857491)<br>          scroller:       a TransformMorph(1206197)<br>             retractableScrollBar:   false<br>         scrollBarOnLeft:        false<br>         getMenuSelector:        #messageListMenu:shifted:<br>             getMenuTitleSelector:   nil<br>           hasFocus:       true<br>          hScrollBar:     a ScrollBar(1080941)<br>          hScrollBarPolicy:       #never<br>                vScrollBarPolicy:       #whenNeeded<br>           scrollBarThickness:     10<br>            list:   #()<br>           fullList:       #()<br>           modelToView:    nil<br>           viewToModel:    nil<br>           getListSelector:        #messageList<br>          getListSizeSelector:    nil<br>           getListElementSelector:         nil<br>           getIndexSelector:       #messageListIndex<br>             setIndexSelector:       #messageListIndex:<br>            keystrokeActionSelector:        #messageListKey:from:<br>         autoDeselect:   true<br>          lastKeystrokeTime:      3750446766632<br>         lastKeystrokes:         ''<br>            lastClickTime:  nil<br>           doubleClickSelector:    nil<br>           handlesBasicKeys:       nil<br>           potentialDropRow:       nil<br>           hoverRow:       1<br>             listMorph:      a LazyListMorph(2282769)<br>              keystrokePreviewSelector:       nil<br>           priorSelection:         14<br>            getIconSelector:        #messageIconAt:<br>               getHelpSelector:        #messageHelpAt:<br>               dragItemSelector:       #dragFromMessageList:<br>         dropItemSelector:       nil<br>           wantsDropSelector:      nil<br>           dragTypeSelector:       nil<br>           dragStartedSelector:    nil<br><br>[] in ProportionalSplitterMorph>>charactersOccludedIn:<br>   Receiver: a ProportionalSplitterMorph(1725805)<br>        Arguments and temporary variables: <br>           aCollection:    0<br>             sum:    a PluggableListMorphPlus(2906921)<br>             each:   0<br>     Receiver's instance variables: <br>           bounds:         929@209 corner: 933@565<br>               owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      #()<br>           fullBounds:     929@209 corner: 933@565<br>               color:  Color transparent<br>             extension:      a MorphExtension (2427553) [other:  (layoutFrame -> a LayoutFrame( l...etc...<br>             handleColor:    nil<br>           handleInset:    nil<br>           lastMouse:      nil<br>           showHandle:     nil<br>           leftOrTop:      an OrderedCollection(a PluggableListMorphPlus(235255))<br>                rightOrBottom:  an OrderedCollection(a PluggableListMorphPlus(2906921))<br>               splitsTopAndBottom:     false<br>         traceMorph:     nil<br>           movements:      an OrderedCollection(1 1 1)<br><br>[] in OrderedCollection(Collection)>>inject:into:<br>        Receiver: an OrderedCollection(a PluggableListMorphPlus(2906921))<br>     Arguments and temporary variables: <br><<error during printing><br>        Receiver's instance variables: <br>           array:  {a PluggableListMorphPlus(2906921) . nil . nil . nil . nil . nil . nil ....etc...<br>             firstIndex:     1<br>             lastIndex:      1<br><br>OrderedCollection>>do:<br>     Receiver: an OrderedCollection(a PluggableListMorphPlus(2906921))<br>     Arguments and temporary variables: <br>           aBlock:         [closure] in OrderedCollection(Collection)>>inject:into:<br>                index:  1<br>     Receiver's instance variables: <br>           array:  {a PluggableListMorphPlus(2906921) . nil . nil . nil . nil . nil . nil ....etc...<br>             firstIndex:     1<br>             lastIndex:      1<br><br>OrderedCollection(Collection)>>inject:into:<br>        Receiver: an OrderedCollection(a PluggableListMorphPlus(2906921))<br>     Arguments and temporary variables: <br>           thisValue:      0<br>             binaryBlock:    [closure] in ProportionalSplitterMorph>>charactersOccludedIn:<br>           nextValue:      #(0)<br>  Receiver's instance variables: <br>           array:  {a PluggableListMorphPlus(2906921) . nil . nil . nil . nil . nil . nil ....etc...<br>             firstIndex:     1<br>             lastIndex:      1<br><br>ProportionalSplitterMorph>>charactersOccludedIn:<br>   Receiver: a ProportionalSplitterMorph(1725805)<br>        Arguments and temporary variables: <br>           aCollection:    an OrderedCollection(a PluggableListMorphPlus(2906921))<br>       Receiver's instance variables: <br>           bounds:         929@209 corner: 933@565<br>               owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      #()<br>           fullBounds:     929@209 corner: 933@565<br>               color:  Color transparent<br>             extension:      a MorphExtension (2427553) [other:  (layoutFrame -> a LayoutFrame( l...etc...<br>             handleColor:    nil<br>           handleInset:    nil<br>           lastMouse:      nil<br>           showHandle:     nil<br>           leftOrTop:      an OrderedCollection(a PluggableListMorphPlus(235255))<br>                rightOrBottom:  an OrderedCollection(a PluggableListMorphPlus(2906921))<br>               splitsTopAndBottom:     false<br>         traceMorph:     nil<br>           movements:      an OrderedCollection(1 1 1)<br><br>ProportionalSplitterMorph>>occlusionDifference<br>   Receiver: a ProportionalSplitterMorph(1725805)<br>        Arguments and temporary variables: <br><br> Receiver's instance variables: <br>           bounds:         929@209 corner: 933@565<br>               owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      #()<br>           fullBounds:     929@209 corner: 933@565<br>               color:  Color transparent<br>             extension:      a MorphExtension (2427553) [other:  (layoutFrame -> a LayoutFrame( l...etc...<br>             handleColor:    nil<br>           handleInset:    nil<br>           lastMouse:      nil<br>           showHandle:     nil<br>           leftOrTop:      an OrderedCollection(a PluggableListMorphPlus(235255))<br>                rightOrBottom:  an OrderedCollection(a PluggableListMorphPlus(2906921))<br>               splitsTopAndBottom:     false<br>         traceMorph:     nil<br>           movements:      an OrderedCollection(1 1 1)<br><br>ProportionalSplitterMorph>>leftRightImbalance<br>    Receiver: a ProportionalSplitterMorph(1725805)<br>        Arguments and temporary variables: <br><br> Receiver's instance variables: <br>           bounds:         929@209 corner: 933@565<br>               owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      #()<br>           fullBounds:     929@209 corner: 933@565<br>               color:  Color transparent<br>             extension:      a MorphExtension (2427553) [other:  (layoutFrame -> a LayoutFrame( l...etc...<br>             handleColor:    nil<br>           handleInset:    nil<br>           lastMouse:      nil<br>           showHandle:     nil<br>           leftOrTop:      an OrderedCollection(a PluggableListMorphPlus(235255))<br>                rightOrBottom:  an OrderedCollection(a PluggableListMorphPlus(2906921))<br>               splitsTopAndBottom:     false<br>         traceMorph:     nil<br>           movements:      an OrderedCollection(1 1 1)<br><br>ProportionalSplitterMorph>>reduceLeftRightImbalance<br>      Receiver: a ProportionalSplitterMorph(1725805)<br>        Arguments and temporary variables: <br>           correction:     nil<br>   Receiver's instance variables: <br>           bounds:         929@209 corner: 933@565<br>               owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      #()<br>           fullBounds:     929@209 corner: 933@565<br>               color:  Color transparent<br>             extension:      a MorphExtension (2427553) [other:  (layoutFrame -> a LayoutFrame( l...etc...<br>             handleColor:    nil<br>           handleInset:    nil<br>           lastMouse:      nil<br>           showHandle:     nil<br>           leftOrTop:      an OrderedCollection(a PluggableListMorphPlus(235255))<br>                rightOrBottom:  an OrderedCollection(a PluggableListMorphPlus(2906921))<br>               splitsTopAndBottom:     false<br>         traceMorph:     nil<br>           movements:      an OrderedCollection(1 1 1)<br><br>ProportionalSplitterMorph>>step<br>  Receiver: a ProportionalSplitterMorph(1725805)<br>        Arguments and temporary variables: <br><br> Receiver's instance variables: <br>           bounds:         929@209 corner: 933@565<br>               owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      #()<br>           fullBounds:     929@209 corner: 933@565<br>               color:  Color transparent<br>             extension:      a MorphExtension (2427553) [other:  (layoutFrame -> a LayoutFrame( l...etc...<br>             handleColor:    nil<br>           handleInset:    nil<br>           lastMouse:      nil<br>           showHandle:     nil<br>           leftOrTop:      an OrderedCollection(a PluggableListMorphPlus(235255))<br>                rightOrBottom:  an OrderedCollection(a PluggableListMorphPlus(2906921))<br>               splitsTopAndBottom:     false<br>         traceMorph:     nil<br>           movements:      an OrderedCollection(1 1 1)<br><br>ProportionalSplitterMorph(Morph)>>stepAt:<br>        Receiver: a ProportionalSplitterMorph(1725805)<br>        Arguments and temporary variables: <br>           millisecondClockValue:  3750446799420<br>         p:      nil<br>   Receiver's instance variables: <br>           bounds:         929@209 corner: 933@565<br>               owner:  a PluggableSystemWindow<Collections-Sequenceable: OrderedDictionary>(259...etc...<br>               submorphs:      #()<br>           fullBounds:     929@209 corner: 933@565<br>               color:  Color transparent<br>             extension:      a MorphExtension (2427553) [other:  (layoutFrame -> a LayoutFrame( l...etc...<br>             handleColor:    nil<br>           handleInset:    nil<br>           lastMouse:      nil<br>           showHandle:     nil<br>           leftOrTop:      an OrderedCollection(a PluggableListMorphPlus(235255))<br>                rightOrBottom:  an OrderedCollection(a PluggableListMorphPlus(2906921))<br>               splitsTopAndBottom:     false<br>         traceMorph:     nil<br>           movements:      an OrderedCollection(1 1 1)<br><br>StepMessage(MorphicAlarm)>>value:<br>        Receiver: StepMessage(#stepAt: -> a ProportionalSplitterMorph(1725805))(a ProportionalSplitterMorph(...etc...<br>      Arguments and temporary variables: <br>           anArgument:     3750446799420<br>         nArgs:  0<br>     Receiver's instance variables: <br>           receiver:       a ProportionalSplitterMorph(1725805)<br>          selector:       #stepAt:<br>              arguments:      nil<br>           scheduledTime:  3750446799418<br>         sequenceNumber:         nil<br>           numArgs:        1<br>             stepTime:       nil<br><br><br>--- The full stack ---<br>Array(Object)>>error:<br>Array(Object)>>errorSubscriptBounds:<br>Array(Object)>>at:<br>PluggableListMorphPlus(PluggableListMorph)>>itemAt:<br>[] in PluggableListMorphPlus(PluggableListMorph)>>visibleList<br>Interval>>collect:<br>PluggableListMorphPlus(PluggableListMorph)>>visibleList<br>PluggableListMorphPlus(PluggableListMorph)>>charactersOccluded<br>[] in ProportionalSplitterMorph>>charactersOccludedIn:<br>[] in OrderedCollection(Collection)>>inject:into:<br>OrderedCollection>>do:<br>OrderedCollection(Collection)>>inject:into:<br>ProportionalSplitterMorph>>charactersOccludedIn:<br>ProportionalSplitterMorph>>occlusionDifference<br>ProportionalSplitterMorph>>leftRightImbalance<br>ProportionalSplitterMorph>>reduceLeftRightImbalance<br>ProportionalSplitterMorph>>step<br>ProportionalSplitterMorph(Morph)>>stepAt:<br>StepMessage(MorphicAlarm)>>value:<br> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -<br>WorldState>>runLocalStepMethodsIn:<br>WorldState>>runStepMethodsIn:<br>PasteUpMorph>>runStepMethods<br>WorldState>>doOneCycleNowFor:<br>WorldState>>doOneCycleFor:<br>PasteUpMorph>>doOneCycle<br>[] in MorphicProject>>spawnNewProcess<br>[] in BlockClosure>>newProcess<br></div>