Calculating PI with Nilakantha formula. *Bug*

[Ronald-Herrera]

A blue screen occur with the attachment sent.

crash-20250629-q1ukok84.log

[Marrin]

I can confirm this issue.

The error is dereferencing a string at address &H1697 which isn't there anymore. That address is very close to the end of the program (&H1653) and there is a string at &HFDCB that's not bound to a variable name, so I guess what happened was that string is the first argument of MID$(), then the creation of the string involved in the third arguments expression triggered a garbage collection that moved the string data of the first argument from &H1697 to &HFDCB but the code still tries to access it at the old address.

That seems to be a bug in PC-BASIC because the programs runs without those problems in GW-BASIC.

[Ronald-Herrera]

Thank you! Happy to help and test. Ron.

…

________________________________ From: Marc Rintsch ***@***.***> Sent: Saturday, July 19, 2025 8:27 AM To: robhagemans/pcbasic ***@***.***> Cc: Ronald-Herrera ***@***.***>; Author ***@***.***> Subject: Re: [robhagemans/pcbasic] Calculating PI with Nilakantha formula. *Bug* (Issue #251) [https://avatars.githubusercontent.com/u/2564163?s=20&v=4]Marrin left a comment (robhagemans/pcbasic#251)<#251 (comment)> I can confirm this issue. The error is dereferencing a string at address &H1697 which isn't there anymore. That address is very close to the end of the program (&H1653) and there is a string at &HFDCB that's not bound to a variable name, so I guess what happened was that string is the first argument of MID$(), then the creation of the string involved in the third arguments expression triggered a garbage collection that moved the string data of the first argument from &H1697 to &HFDCB but the code still tries to access it at the old address. That seems to be a bug in PC-BASIC because the programs runs without those problems in GW-BASIC. — Reply to this email directly, view it on GitHub<#251 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/BUDDMALLOS6EQAFI7KA32C33JI2TDAVCNFSM6AAAAACAMTDJ7WVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTAOJSGMZDKMJTGQ>. You are receiving this because you authored the thread.Message ID: ***@***.***>