bz2: Initialize variables

There is a small chance that we might end up in the done step without
having any output available.

Furthermore, when going through not_ready, we need to ensure gst_buffer_unmap
has a properly initialized GstMapInfo.

CID #1139923
CID #1139924
CID #1139919
CID #1139920
mpeg2enc: Add missing break in switch

QUERY_CAPS is fully handled, we don't need to passthrough to the default
handler.

CID #1139756
rsvg: Add missing break in switch statement

This wasn't fatal before (worst case it would clear an already empty
adapter).

CID #1139758
soundtouch: Add missing break in switch

Whoops, modifying the pitch when modifying the output rate ...

CID #1139749
speed: Clarify passthrough in switch statement

We do want the caps event to be forwarded downstream

CID #1139754
festival: fix fd leak

Coverity 1139831
directsoundsrc: Fix critical due to missing debug category initialization

https://bugzilla.gnome.org/show_bug.cgi?id=727812
dtsdec: fix buffer overflows

Channels can be up to 7. Also add a guard in case more can be
returned in the future.

Coverity 1139820, 1139821
mxfdemux: fix seeking, send data starting from a key unit

Fixes multiple seeking issues. When doing ACCURATE or normal
non-KEYUNIT seeks, mxfdemux would just send data from the
edit unit that covered the seek position, whether that's
a keyframe or not. Decoders would only output things from
the next keyframe then, which means there's a gap between
the start of the segment and the first decoded data in
some cases. In combination with gst-editing-services this
might result in a frozen picture for the duration of that
gap at the beginning (if videorate fixes up the first
buffer's start timestamp to cover the entire gap), or
a black frame (if no videorate is used and videomixer
fills the gap). Also fixes A/V sync issue when requesting
a KEYUNIT seek.
resindvd: guard against overflow in menu subtitle streams

There is space for a single subtitle stream, but up to 255
may be used based on a uint8_t value in a struct, which may
or may not be read from the (untrusted) data.
A comment in ifo_types.h says this value is either 0 or 1, so
we can ensure this here without drawbacks.

Coverity 1139586
resindvd: guard against overflow in audio subtitle streams

Turns out there was the same issue as with subtitles.

There is space for a single audio stream, but up to 255
may be used based on a uint8_t value in a struct, which may
or may not be read from the (untrusted) data.
A comment in ifo_types.h says this value is either 0 or 1, so
we can ensure this here without drawbacks.

Coverity 1139585
mxfdemux: implement simple KEY_UNIT seeking

If a KEY_UNIT seek was requested, adjust segment
start to position of the key frame.
dvb: reject too long socket paths

Coverity 206004
gl: fix leaks

As the relevant variables are initialized to 0/NULL, we can loop
over the full range and make sure we free partial allocations
when an error happens partway through initialization.
dvb: fix compilation
dvbsuboverlay: Avoid infinite loops on short data
gl: test for frame NULLness before dereferencing it

Coverity 1195172, 1195171
hls: bring NULL test before dereference

Coverity 1195168
mxfdemux: guard against NULL material track

Just to be on the safe side.
hls: only set DISCONT flag on a valid buffer

Recent refactoring causes this code to be called with either a NULL
fragment, or a non NULL fragment. In the former case, we don't have
a buffer. In the latter case, the original code dealing with DISCONT
assumed the buffer was valid. Testing for a NULL buffer here thus
does not seem to change the intent, and fixes:

Coverity 1195147