Matteo Beniamino
Pressing a trigger button on a Steam Controller causes a segmentation fault both with stable version and latest mercurial head on Linux. I'm using the recent hid_steam kernel module with lizard_mode disabled (that is no keyboard/mouse emulation). I suspect this is what's happening: the driver exposes two hats. The two hats have indices 0 and 2. Inside linux/SDL_sysjoystick.c two hats are allocated in allocate_hatdata for joystick->hwdata->hats. In HandleHat function the hat parameter (that can be 2) is directly used as the index of the array that only has two elements, causing an out of bounds access. SDL is not expecting to have "holes" between hats indices.
The index 2 is calculated in HandleInputEvents() as (ABS_HAT2X - ABS_HAT0X) / 2 where ABS_HAT2X is the value associated to the hat inside the hid_steam module.
Noam Preil
In src/joystick/linux/SDL_sysjoystick.c:
The ConfigJoystick function's axes detection starts with a for loop using an index i for Linux's axes names. When i gets to ABS_HAT0X, it's set to ABS_HAT3Y and a continue statement appears, to skip the hats. This makes sense, as SDL handles hats separately from axes.
However, in PollAllValues, *two* indices are used: a and b. Both start out the same, and remain so until the hats are reached. At that point, a becomes identical to the i from ConfigJoystick's loop, but b is equal to a - (ABS_HAT3Y - ABS_HAT0X), or a - 8.
While all the joystick->hwdata->abs_* structures in ConfigJoystick used i - which would here be a - as both the index and the ioctl argument, PollAllValues uses b for the structure index and a as the ioctl argument.
It would appear, however, that no joystick HAS such axes, and that the b index is entirely unnecessary.
I tested three separate joysticks, and while that was far from a complete listing, I was unable to find a joystick with an axis above 0x08.
maxxus
The Dualshock 3's motion sensors don't seem to be reported by the call to EVIOCGBIT but they still send EV_ABS events. Because they're not reported by EVIOCGBIT they're not assigned a proper axis ids and the default of 0 is used, which is the valid id for the left analog sticks left/right axis.
The code is now reliant on SDL_PrivateJoystickAdded() and SDL_PrivateJoystickRemoved() being called correctly when devices are added or removed on Windows
Author: James Zipperer <james.zipperer@synapse.com>
Date: Sun Aug 21 01:19:19 2016 -0700
bugfix for controller / joystick add / remove being in the event queue at the same time
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
Sam Lantinga
Andrew Eikum
Cameron Gutman
Ryan C. Gordon
Philipp Wiesemann