Avoid a type mismatch that shows up in C++11.
Taken from <https://bugs.debian.org/853560>.

--- a/src/rtphint.cpp	2012-05-20 16:11:53.000000000 -0600
+++ b/src/rtphint.cpp	2017-05-16 10:25:26.930705191 -0600
@@ -339,7 +339,7 @@
                 pSlash = strchr(pSlash, '/');
                 if (pSlash != NULL) {
                     pSlash++;
-                    if (pSlash != '\0') {
+                    if (*pSlash != '\0') {
                         length = (uint32_t)strlen(pRtpMap) - (pSlash - pRtpMap);
                         *ppEncodingParams = (char *)MP4Calloc(length + 1);
                         strncpy(*ppEncodingParams, pSlash, length);
value='7304d5623ab5cc35289cb1535cbd0d8a37691fac'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>refs</a><a class='active' href='/guix/log/gnu/build/linux-container.scm'>log</a><a href='/guix/tree/gnu/build/linux-container.scm?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>tree</a><a href='/guix/commit/gnu/build/linux-container.scm?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>commit</a><a href='/guix/diff/gnu/build/linux-container.scm?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/build/linux-container.scm'>
<input type='hidden' name='id' value='7304d5623ab5cc35289cb1535cbd0d8a37691fac'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>root</a>/<a href='/guix/log/gnu?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>gnu</a>/<a href='/guix/log/gnu/build?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>build</a>/<a href='/guix/log/gnu/build/linux-container.scm?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac'>linux-container.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/build/linux-container.scm?id=7304d5623ab5cc35289cb1535cbd0d8a37691fac&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-07-06 00:26:58 +0200'>2019-07-06</span></td><td><a href='/guix/commit/gnu/build/linux-container.scm?id=935e79af61f4d903e562362cdd828be807e15581'>linux-container: Mount a new /dev/pts instance in the container.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/36463&gt;.
Reported by Steffen Rytter Postas &lt;nc@scalehost.eu&gt;.

* gnu/build/linux-container.scm (mount-file-systems): When /dev/ptmx
exists on the host, explicitly mount a new instance of devpts and make
/dev/ptmx a symlink to /dev/pts/ptmx.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-06-23 19:53:03 +0200'>2019-06-23</span></td><td><a href='/guix/commit/gnu/build/linux-container.scm?id=40c369b23442ace588d8c85f62f1741c17ed65c0'>linux-container: Remove dependency on (guix utils).</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes a bug whereby derivations importing (gnu build linux-container),
such as the 'bitlbee' and 'tor' services, would depend on the
user's (guix config) file, which was pulled as a dependency of (guix
utils).  As a result, those derivations would vary from user to user.

* gnu/build/linux-container.scm (call-with-temporary-directory): New
procedure.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-04-02 18:15:37 +0200'>2019-04-02</span></td><td><a href='/guix/commit/gnu/build/linux-container.scm?id=af76c020bf19de5fe2e92f31d8b85cbd55c481de'>linux-container: Make the guest UID and GID a parameter.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/linux-container.scm (initialize-user-namespace): Add
 #:guest-uid and #:guest-gid parameters and honor them.
(run-container): Likewise.
(call-with-container): Likewise.
* tests/containers.scm ("call-with-container, user namespace, guest UID/GID"):
New test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-01-15 23:29:33 +0100'>2018-01-15</span></td><td><a href='/guix/commit/gnu/build/linux-container.scm?id=95aa64bc48cae061effafa7675ea9d9ccbe311a4'>linux-container: Work around EBADF errors upon exit.</a><span class='msg-avail'>...<span class='msg-tooltip'>Typically 'read-pid-file/container' would fail when starting services in
containers such as BitlBee.

* gnu/build/linux-container.scm (call-with-clean-exit): Use
'primitive-_exit' instead of 'primitive-exit'.
(container-excursion*): Close OUT.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-10-11 11:12:33 +0200'>2017-10-11</span></td><td><a href='/guix/commit/gnu/build/linux-container.scm?id=1c65cca5743e9171bbd94307195f123d26c0535e'>file-systems: 'mount-file-system' now takes a &lt;file-system&gt; object.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/file-systems.scm (mount-file-system): Rename 'spec' to 'fs'
and assume it's a &lt;file-system&gt;.
* gnu/build/linux-boot.scm (boot-system): Assume MOUNTS is a list of
&lt;file-system&gt; and adjust accordingly.
* gnu/build/linux-container.scm (mount-file-systems): Remove
'file-system-&gt;spec' call.
* gnu/services/base.scm (file-system-shepherd-service): Add
'spec-&gt;file-system' call.  Add (gnu system file-systems) to 'modules'.
* gnu/system/linux-initrd.scm (raw-initrd): Use (gnu system
file-systems).  Add 'spec-&gt;file-system' call for #:mounts.
</span></span></td><td>Ludovic Courtès</td></tr>