09111: All systems that have cassette support: If a non-existing cassette file is specified, a 0-byte file gets created

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
09111	Media Support	Minor	Always	9 days ago	2 days ago

Tester	Robbbert	View Status	Public	Platform	MAME (Self-compiled)
Assigned To		Resolution	Open	OS	Windows 10/11 (64-bit)
Status [?]	Direction Needed			Driver
Version	0.274	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	09111: All systems that have cassette support: If a non-existing cassette file is specified, a 0-byte file gets created
Description	On any system that supports cassettes, if a file that doesn't exist was accidentally specified on the command line, an unwanted zero-byte file gets left behind. I've used super80 in the examples below, but any cassette-supporting system can be used.
Steps To Reproduce	If you didn't specify a folder then the MAME folder gets used. >mame super80 -cass t Firstly it lists a bunch of nearly matching software items. Then it says: Unable to load image 't': No such file or directory (generic:2) This isn't fatal: the emulation starts up. MAME creates an empty file and loads it into the file manager. If you now quit, the zero-byte file gets left behind. >dir t Directory of C:\MAME 2025-02-12 20:13 0 t ----------------- Now, we specifiy a folder that exists: >mame super80 -cass temp\t This time there's no software list suggestions; it just says: Unable to load image 'temp\t': No such file or directory (generic:2) Again, a zero-byte file is left behind. ------------------ Now we specifiy a folder that doesn't exist >mame super80 -cass temp2\t Unable to load image 'temp2\t': No such file or directory (generic:2) Unable to create image 'temp2\t': No such file or directory (generic:2) Fatal error: Device Cassette load (-cassette ) failed: No such file or directory (generic:2) This is fatal. You can see that it tries to create a file.
Additional Information	What happens above is almost right, but I'd suggest that a new file gets created only if it was written to. Leaving zero-byte files littering the system is untidy at best. Other missing media (eg floppies) don't create empty files. Also note that MAME will allow creation and usage of files that don't have approved extensions, and thus cannot be used for reading later.
Github Commit

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Regression Version
Affected Sets / Systems	All systems that have cassette support

Attached Files

No.23018 AJR Developer 2 days ago edited on: 2 days ago	The suggestion does not seem very workable given MAME's current handling of image files. Creating the file at the moment the image is first written to creates overhead where overhead is not desirable. Removing the file if it ends up as empty could perhaps be done, but MAME is not alone in exhibiting the "untidy" behavior of creating 0-byte files, which might even be correct for some uses. Floppy disks are treated differently in this regard due to support_command_line_image_creation() returning false for their image device. Currently the core does not appear to actually enforce the list of supported extensions, leaving it up to the image devices to reject files without approved extensions. Perhaps the core should check it when trying to create a new image file from a command line parameter.

No.23018

AJR

Developer

2 days ago

edited on: 2 days ago

The suggestion does not seem very workable given MAME's current handling of image files. Creating the file at the moment the image is first written to creates overhead where overhead is not desirable. Removing the file if it ends up as empty could perhaps be done, but MAME is not alone in exhibiting the "untidy" behavior of creating 0-byte files, which might even be correct for some uses.

Floppy disks are treated differently in this regard due to support_command_line_image_creation() returning false for their image device.

Currently the core does not appear to actually enforce the list of supported extensions, leaving it up to the image devices to reject files without approved extensions. Perhaps the core should check it when trying to create a new image file from a command line parameter.