mythfrontend crashes on startup for nvidia if any modeline has name like FOO-1080

[gavin@…]

If you have modelines of the form FOO-1080, then you'll segfault in the strstr() call in modeline_is_interlaced.

It's apparently caused by a bug in parse_mode_string, which finds the wrong modestring in this case, causing find_modeline to error out, causing pain. See the for loop in parse_mode_string and the checks with isdigit.

I was having segfaults on every startup; I can reproduce this (and hopefully almost anyone else can) if you want more information.

[anonymous]

(err, some context: all above function names are in util-nvctrl.cpp).

[JYA]

backtrace please ?

[gavin@…]

I'll get you one this evening. I'm surprised you're having trouble reproducing this!

[gregorio.gervasio@…]

Can't provide a backtrace myself right now but the segfault is because find_modeline() returns NULL if it doesn't find a match and modeline_is_interlaced() cannot handle a NULL argument.

[JYA]

(In [21579]) Handle additional modeline entries. Handle wierd modlines that could include several ' @' in the name. Should handle all modelines now , added a safeguard if it doesn't.

Fix #6926

[JYA]

Unfortunately, I couldn't find any references on what the name of a modeline entry can contain.

The structures returned by NV-CTRL doesn't contain any delimiters around the name. It's in the form: DFP-1: 1280x720 @1280x720 +0 +0

so I now assume that the name is contained between the first space and the last ' @'. The fix now handles modeline like: DFP-1: 1280x720@ 50 @blah @1280x720 +0 +0

Added safeguard in case the name isn't retrieved properly, and the modeline will simply be ignored.

Fixed in [21579]