07894: UI: Doesn't show missing files/CHDs for clone sets

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
07894	Interface	Minor	Always	Mar 4, 2021, 20:50	Mar 9, 2021, 14:33

Tester	Foxhack	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS
Status [?]	Confirmed			Driver
Version	0.229	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	07894: UI: Doesn't show missing files/CHDs for clone sets
Description	If a parent romset that uses a CHD is missing the CHD, then MAME will say what files are missing. But if you do the same with a clone set that is also missing files, it doesn't say what exact files are missing.
Steps To Reproduce	Select Wayne Gretzky's 3D Hockey. In my setup, I have the romset but the CHD is missing. Selecting it in MAME will tell me that required ROM / disk images are missing, and it says the CHD is missing. Now select Wayne Gretzky's 3D Hockey Fatality Edition (prototype) - it will say that required ROM/disk images are missing, but it won't actually say which ones are missing. It should say "you don't have the wg3dhfe.chd file" but it just... doesn't. Attempting to run the same drivers from the command line -does- show that you are missing the CHD files. I tried this with a few other "clones with CHD" games, like the Beatmania sets, and they all appeared to have the same issue.
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	UI

Attached Files	wg3dherror.png (210,920 bytes) Mar 4, 2021, 20:50 Uploaded by Foxhack

No.18512 Robbbert Senior Tester Mar 5, 2021, 04:24 edited on: Mar 5, 2021, 04:27	Issue confirmed. Also, the filename in the message is incorrect - ".chd" is missing. Further, the error is printed to the console and the filename is wrong there too. So, 3 bugs in one report.
No.18515 cuavas Administrator Mar 6, 2021, 09:26	This is not a bug. MAME doesn’t itemise missing files if the audit reports the set as not found. We have logic to report clones as not found if you don’t have any files that are part of the clone set but not part of the parent set. The same logic is used for `-verifyroms` on the command line as well as for the audit when selecting a system from the UI. Originally this was implemented to discourage PokéROMming and to reduce clutter in the output, but people seem to like the behaviour. In fact, we had a series of bug reports complaining that MAME listed missing files for clone sets that aren’t present. An attempt to suppress them led to some systems incorrectly being reported as not found even if the ROMs were all present, which sadly made it into a release (see MT07410, MT07756 and GitHub #7314). The lack of the .chd extension on disk images is another thing that’s not really a bug per se. It’s never been included for disk images in listings. Speculating, I’d say it was originally done this way because the CHD format is an implementation detail, and we could conceivably adapt to support different disk image formats. We also don’t include an extension for device/system names because we support a folder, a zip archive, or a 7zip archive. There’s nothing in this report that isn’t intended behaviour.
No.18516 Robbbert Senior Tester Mar 6, 2021, 11:30	Is this intended behaviour documented? If a clone doesn't show what's missing, how is a user to know that they need to refer to the parent for guidance? If xyz.chd is missing, and the report says that xyz is missing, how would the user know that it's a chd and they should somehow know they have to find xyz.chd instead? What if they were under the impression that a rom called xyz was the one missing? It's isn't being helpful to leave out part of the filename. Lastly, why do we care about the doings of pokerommers? It isn't our concern.
No.18517 cuavas Administrator Mar 6, 2021, 13:16	If there are no ROMs specific to the clone missing, they don’t have the clone set at all and need to get it. They don’t need to look at the parent for guidance. In this case, they have no files specific to wg3dhfe, only files from wg3dh. This is treated as the clone set being absent.
No.18518 Foxhack Tester Mar 6, 2021, 19:29 edited on: Mar 6, 2021, 19:30	"This is treated as the clone set being absent." I understand the logic. But I'm not sure I agree with the way it's reported. If the entire romset (or in this case, the required CHD that makes up the clone set) is missing, then the UI should specifically say "Dude, this isn't here. You can't run it." The way you worded things in your first post implies that it's not feasible to list the missing files from the clone set, but is it possible to show a different output if required files are missing or if the entire set is missing, since that's two different scenarios?
No.18528 cuavas Administrator Mar 9, 2021, 14:33	I guess we can change it to show a different message for a “not found” audit result.