The custom mutex definition in Seq24 clashes with the mutex defined in gtkmm.
This patch renames the custom definition.

See https://bugs.launchpad.net/seq24/+bug/1647614 for upstream bug report.

diff --git a/src/midibus.h b/src/midibus.h
index 2cdf8e8..1bb02bd 100644
--- a/src/midibus.h
+++ b/src/midibus.h
@@ -90,7 +90,7 @@ class midibus
 
 
     /* locking */
-    mutex m_mutex;
+    seq24mutex m_mutex;
 
     /* mutex */
     void lock();
@@ -208,7 +208,7 @@ class mastermidibus
     sequence *m_seq;
 
     /* locking */
-    mutex m_mutex;
+    seq24mutex m_mutex;
 
     /* mutex */
     void lock();
diff --git a/src/midibus_portmidi.h b/src/midibus_portmidi.h
index 0119e9c..8c6a27a 100644
--- a/src/midibus_portmidi.h
+++ b/src/midibus_portmidi.h
@@ -65,7 +65,7 @@ class midibus
     long m_lasttick;
 
     /* locking */
-    mutex m_mutex;
+    seq24mutex m_mutex;
 
     /* mutex */
     void lock();
@@ -164,7 +164,7 @@ class mastermidibus
     sequence *m_seq;
 
     /* locking */
-    mutex m_mutex;
+    seq24mutex m_mutex;
 
     /* mutex */
     void lock();
diff --git a/src/mutex.cpp b/src/mutex.cpp
index b3f23fd..914114f 100644
--- a/src/mutex.cpp
+++ b/src/mutex.cpp
@@ -20,23 +20,23 @@
 
 #include "mutex.h"
 
-const pthread_mutex_t mutex::recmutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
+const pthread_mutex_t seq24mutex::recmutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
 const pthread_cond_t condition_var::cond  = PTHREAD_COND_INITIALIZER;
 
-mutex::mutex( )
+seq24mutex::seq24mutex( )
 {
     m_mutex_lock = recmutex;
 }
 
 void
-mutex::lock( )
+seq24mutex::lock( )
 {
     pthread_mutex_lock( &m_mutex_lock );
 }
 
 
 void
-mutex::unlock( )
+seq24mutex::unlock( )
 {
     pthread_mutex_unlock( &m_mutex_lock );
 }
diff --git a/src/mutex.h b/src/mutex.h
index 399f8a3..4f1b867 100644
--- a/src/mutex.h
+++ b/src/mutex.h
@@ -24,7 +24,7 @@
 
 #include <pthread.h>
 
-class mutex {
+class seq24mutex {
 
 private:
 
@@ -37,14 +37,14 @@ protected:
 
 public:
 
-    mutex();
+    seq24mutex();
 
     void lock();
     void unlock();
 
 };
 
-class condition_var : public mutex {
+class condition_var : public seq24mutex {
 
 private:
 
diff --git a/src/sequence.h b/src/sequence.h
index 2943946..9da8700 100644
--- a/src/sequence.h
+++ b/src/sequence.h
@@ -153,7 +153,7 @@ class sequence
     long m_rec_vol;
 
     /* locking */
-    mutex m_mutex;
+    seq24mutex m_mutex;
 
     /* used to idenfity which events are ours in the out queue */
     //unsigned char m_tag;
</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-02-22 12:07:45 +0100'>2021-02-22</span></td><td><a href='/guix/commit/tests/guix-lint.sh?id=9a38bed2cf32e9462badfa43e74cdd4580e804fc'>packages: 'package-field-location' handles 'search-path' returning #f.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/46390&gt;.
Reported by zimoun &lt;zimon.toutoune@gmail.com&gt;.

This is similar to the fix in d10474c38d58bdc676e64336769dc2e00cdfa8ed.

* guix/packages.scm (package-field-location): Handle FILE not in %LOAD-PATH.
* tests/guix-lint.sh: Add test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-09-28 21:06:36 -0500'>2020-09-28</span></td><td><a href='/guix/commit/tests/guix-lint.sh?id=d8934360d2453a403b5433e71d09188e4ed23b57'>tests: Simplify shell exit status negation;</a><span class='msg-avail'>...<span class='msg-tooltip'>* tests/guix-archive.sh, tests/guix-build-branch.sh, tests/guix-build.sh,
tests/guix-daemon.sh, tests/guix-download.sh, tests/guix-environment.sh,
tests/guix-gc.sh, tests/guix-git-authenticate.sh, tests/guix-graph.sh,
tests/guix-hash.sh, tests/guix-lint.sh, tests/guix-pack-relocatable.sh,
tests/guix-pack.sh, tests/guix-package-aliases.sh, tests/guix-package-net.sh,
tests/guix-package.sh: Use the shell '!' keyword to negate command exit status
in place of 'if ...; then false; else true; fi'
</span></span></td><td>Eric Bavier</td></tr>
<tr><td><span title='2020-08-23 23:05:16 +0200'>2020-08-23</span></td><td><a href='/guix/commit/tests/guix-lint.sh?id=d10474c38d58bdc676e64336769dc2e00cdfa8ed'>lint: formatting: Gracefully handle relative file names.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/42543&gt;.
Reported by Jack Hill &lt;jackhill@jackhill.us&gt;.

* guix/lint.scm (check-formatting): Always return a list (previously we
would return #f when 'search-path' returns #f).  Check whether
LOCATION's file is a relative file name.  Return a warning if not.
* tests/guix-lint.sh: Add test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-12-08 23:14:03 +0100'>2019-12-08</span></td><td><a href='/guix/commit/tests/guix-lint.sh?id=7282f9496793227d7ac6f902976aecb663068ec1'>lint: Add '--load-path' option.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/scripts/lint.scm (%options): Add '--load-path' option.
* doc/guix.texi: Document it.
* tests/guix-lint.sh: Test it.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>zimoun</td></tr>