Wimp Crash in Writable Icons

I seem to have stumbled across¹ another piece of icon clipboard crashiness in the Wimp. Find yourself a writeable menu entry (save your work first), and with the caret inside it, press Ctrl-K.

Where I initially found this, in the Filer’s Rename and Set Type menu entries, there’s an Abort on Data Transfer reported at &FC124AB8 or &FC124ABC, which is offset &1397C or &13980 in WindowManager 5.73. That appears to be somewhere around the LDRB or STRB by the 01 label at this code from Wimp05.

clipboard_wdelete_perform
        Push    "R0-R6,R14"

        ; cut from icon text
        LDR     R5,[handle,#w_seldata+wsellowindex]
        Push    "R5"            ; we want this shortly for the main caret
        LDR     R6,[handle,#w_seldata+wselhighindex]

        ; move data down from r2+r6 to r2+r5
        ; pointer to byte post terminator is r4
        ; maximum length is r7
        ADD     R5,R5,R2
        ADD     R6,R6,R2

01
        LDRB    R0,[R6],#1
        STRB    R0,[R5],#1
        TEQ     R6,R4
        BNE     %BT01

I then tried a writeable menu field in Draw’s font size menu, and locked the machine up.

The problem is present in a 5.27 ROM dated 7 May 2020.

¹ It was actually reported to me as a bug in IcnClipBrd. That was my initial assumption, too – until discovering that the problem was still present without IcnClipBrd having been loaded since boot.

On (re)naming a directory; ‘abort on data transfer at &FC13B2C4’. 05-05-20 ROM

Find yourself a writeable menu entry […]

Actually, forget what I said about writeable menu entry. For some reason I just tried Ctrl-K in a normal writeable icon, and a similar problem appears to show up there, too.

It’s there in windowmanager 5.65 already (~dec 18, 2019) at offset 138A8, same LDRB R0/STRB R0 location. Wimp 5.64, Nov 2019, is good, no similar code therein it seems.

Thanks for the report. I’ve submitted a merge request for a possible fix. There is now a sanity check on ^K and ^X to check that there really is a selection present before trying to arrange any text removal from the icon.

I’ve submitted a merge request for a possible fix.

Thanks! I’ll have a look when the new build arrives.