Hi Bob & David,

Thanks for all your help with this.

The runs are short because in my original fileOut, the class was named MoodleClient, but I hand-edited the .cs to rename it FooClient and to remove all my proprietary methods I'm not yet ready to share.

I did try to explain this in my original post which is now in the distant realm of the thread.  :)

Best,
Tim

On Jul 4, 2018, at 3:55 PM, Bob Arning wrote:

> A little more...
> 
> This problem may ultimately be due to something broken in the text being displayed. If I look at the funky class comment, it has these runs
> 
> a RunArray runs: #(1 35 18 20 3) values: {#() . {a TextFontChange font: 1} . #() . {a TextEmphasis code: 1} . #()}
> 
> The total length of the run sizes is 77, yet the string is only 70 bytes long.
> 
> If I copy that text out and paste into a workspace, the runs now look like:
> 
> a RunArray runs: #(1 35 18 16) values: {#() . {a TextFontChange font: 1} . #() . {a TextEmphasis code: 1}}
> 
> and the size of the runs matches the size of the string at 70. I wonder if other occurrences of this problem might have a similar cause.
> 
> On 7/4/18 4:20 PM, David T. Lewis wrote:
>> On Wed, Jul 04, 2018 at 03:46:16PM -0400, Bob Arning wrote:
>>> Here is a side-by-side comparison with the styled version on the right 
>>> and the same text unstyled on the left. Note the difference in runStopIndex
>>> 
>> I see it now. Thanks!
>> 
>> Dave
>> 
>> 
>>> On 7/4/18 2:49 PM, David T. Lewis wrote:
>>>> I tried reverting #scanCharactersFrom:to:in:rightX:stopConditions:kern:
>>>> to the earlier version (cmm 6/12/2010 11:52), but I still get failures
>>>> with cursor and mouse in the class comment text when browsing the FooClient
>>>> class. There must be something else going on here, and it is certainly
>>>> not obvious to me why it is happening only with the FooClient test
>>>> example.
>>>> 
>>>> Dave
>>>> 
>>>> On Wed, Jul 04, 2018 at 02:10:00PM -0400, Bob Arning wrote:
>>>>> perhaps this will help:
>>>>> 
>>>>> This version does not seem to exhibit the error and it limits stopIndex
>>>>> to the size of the string
>>>>> 
>>>>> !CharacterScanner methodsFor: 'scanning' stamp: 'cmm 6/12/2010 11:52'!
>>>>> scanCharactersFrom: startIndex to: stopIndex in: sourceString rightX:
>>>>> rightX stopConditions: stops kern: kernDelta
>>>>> 
>>>>> ?????? | startEncoding selector |
>>>>> ?????? (sourceString isByteString) ifTrue: [^ self
>>>>> basicScanCharactersFrom: startIndex *to: (stopIndex min: sourceString
>>>>> size)* in: sourceString rightX: rightX stopConditions: stops kern:
>>>>> kernDelta.].
>>>>> 
>>>>> ?????? (sourceString isWideString) ifTrue: [
>>>>> ?????? ?????? startIndex > stopIndex ifTrue: [lastIndex := stopIndex. ^
>>>>> stops endOfRun].
>>>>> ?????? ?????? startEncoding :=?? (sourceString at: startIndex) 
>>>>> leadingChar.
>>>>> ?????? ?????? selector := EncodedCharSet scanSelectorAt: startEncoding.
>>>>> ?????? ?????? ^ self perform: selector withArguments: (Array with:
>>>>> startIndex with: stopIndex with: sourceString with: rightX with: stops
>>>>> with: kernDelta).
>>>>> ?????? ].
>>>>> 
>>>>> ?????? ^ stops endOfRun
>>>>> ! !
>>>>> 
>>>>> This version fails and does not limit the stopIndex.
>>>>> 
>>>>> !CharacterScanner methodsFor: 'scanning' stamp: 'nice 10/22/2013 20:49'!
>>>>> scanCharactersFrom: startIndex to: stopIndex in: sourceString rightX:
>>>>> rightX
>>>>> ?????? ^sourceString scanCharactersFrom: startIndex *to: stopIndex* with:
>>>>> self rightX: rightX font: font! !
>>>>> 
>>>>> 
>>>>> On 7/4/18 11:53 AM, David T. Lewis wrote:
>>>>>> On Wed, Jul 04, 2018 at 02:35:59PM +0200, karl ramberg wrote:
>>>>>>> On Wed, Jul 4, 2018 at 11:10 AM K K Subbu <kksubbu.ml at gmail.com> wrote:
>>>>>>> 
>>>>>>>> On Tuesday 03 July 2018 04:40 AM, Tim Johnson wrote:
>>>>>>>>> 1. File-in the .cs as attached*.
>>>>>>>>> 2. In a system browser, click on the class, then click on the [?] 
>>>>>>>>> button
>>>>>>>>> to view class comment.
>>>>>>>>> 3. Notice the styled text in the comment.
>>>>>>>>> 4. Click around the comment pane a bit.
>>>>>>>>> 5. Eventually, see "Error: subscript is out of bounds: 71" appear over
>>>>>>>>> and over until you interrupt.
>>>>>>>> In step 4, it is sufficient to click once near the bottom of the pane
>>>>>>>> when the cursor changes from I-bar to arrow and then wait. This will
>>>>>>>> trigger the error, but the error window triggers itself recursively
>>>>>>>> around 50 times before stopping and displaying the windows.
>>>>>>>> 
>>>>>>>> I added an assert to catch it before recursion:
>>>>>>>> 
>>>>>>>>     self assert: lastIndex < sourceString size.
>>>>>>>> 
>>>>>>>> The assert window itself throws up another error, but that is a topic
>>>>>>>> for another thread ;-).
>>>>>>>> 
>>>>>>>> Regards .. Subbu
>>>>>>> Hi,
>>>>>>> See class comment i NewParagraph for a hint of what happens.
>>>>>>> A empty lineSpan 71 to: 70 is added to the end of the paragraph, when 
>>>>>>> you
>>>>>>> double click below the text.
>>>>>>> When the character scanner looks for characters outside of the string at
>>>>>>> index 71 it cause a recursion.
>>>>>>> 
>>>>>>> Best,
>>>>>>> Karl
>>>>>>> 
>>>>>> Good tiip to look at the NewParagraph class comment, there is apparently
>>>>>> some left over messiness in here somewhere.
>>>>>> 
>>>>>> Another way to trigger the bug using the test case with FooClient is
>>>>>> to position the cursor in the comment pane and use keyboard right cursor
>>>>>> to move to the end of the comment. This causes the same bounds error but
>>>>>> takes a different path through the code leading to the error.
>>>>>> 
>>>>>> Looking through the stack in a debugger after triggering the error with
>>>>>> the mouse, here are a few notes (but no conclusions):
>>>>>> 
>>>>>> On mouseUp: we enter Editor>>selectWord then call
>>>>>> Editor>>selectWordLeftDelimiters:rightDelimiters:
>>>>>> which has this:
>>>>>> 
>>>>>> 	"Select the whole text when clicking before first or after last
>>>>>> 	character"
>>>>>> 	(here > string size or: [here < 2]) ifTrue: [^self selectFrom: 1 to:
>>>>>> 	string size].
>>>>>> 
>>>>>> where string is the 70 character String derived from the Text.
>>>>>> 
>>>>>> At this point we are trying to select from 1 to 70 (the whole string for
>>>>>> the entire text) in TextEditor>>selectFrom:to:
>>>>>> 
>>>>>> This calls Editor>>selectInvisiblyFrom:to: and here the stop index is
>>>>>> set past the size of the string:
>>>>>> 
>>>>>>   selectInvisiblyFrom: start to: stop
>>>>>>      "Select the designated characters, inclusive.  Make no visual
>>>>>>      changes."
>>>>>> 
>>>>>>      self markIndex: start pointIndex: stop + 1
>>>>>> 
>>>>>> From this point we are trying to go from index 1 to index 71 over a 
>>>>>> string
>>>>>> of size 70, and eventually end up with the out of bounds exception.
>>>>>> 
>>>>>> A clue that this might be accumulation of kludges: Looking at senders of
>>>>>> selectInvisiblyFrom:to: (such as TextEditor>>addText:event:) shows a 
>>>>>> number
>>>>>> of methods that subtract 1 from the stop index when before calling the
>>>>>> method
>>>>>> that adds 1 back to the stop index. This certainly does not have a good
>>>>>> smell.
>>>>>> 
>>>>>> It is not clear to me why selectInvisiblyFrom:to: would be adding one to
>>>>>> the
>>>>>> stop index, but I see that the method stamp is jmv 5/27/2011, which
>>>>>> suggests
>>>>>> to me that we should take a look at Cuis to figure out how this is 
>>>>>> intended
>>>>>> to function. Cuis does not show any cases of senders of
>>>>>> selectInvisiblyFrom:to:
>>>>>> that subtract 1 from the stop index, and the Cuis implementation of
>>>>>> selectInvisiblyFrom:to: is that same as Squeak.
>>>>>> 
>>>>>> Dave
>>>>>> 
>>>>>> 
>> 
> 
> 

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