gnu: esound: Fix build.

* gnu/packages/patches/esound-c99.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/gstreamer.scm (esound): Apply it.

Change-Id: I6aa9ccda6e9948961b6e0011ebd813f43de1b18d

gnu/local.mk

@@ -1239,6 +1239,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/erlang-man-path.patch			\
   %D%/packages/patches/esmini-use-pkgconfig.patch		\
   %D%/packages/patches/esmtp-add-lesmtp.patch		\
+  %D%/packages/patches/esound-c99.patch         		\
   %D%/packages/patches/exercism-disable-self-update.patch	\
   %D%/packages/patches/extempore-unbundle-external-dependencies.patch	\
   %D%/packages/patches/extundelete-e2fsprogs-1.44.patch		\

gnu/packages/gstreamer.scm

@@ -304,7 +304,8 @@ applications that want audio visualisation and audio visualisation plugins.")
          (commit "ESOUND_0_2_41")))
        (file-name (git-file-name name version))
        (sha256
-        (base32 "141jg70fim276i8k2kyypm84gy89i1k9mm4yf68mfwnybvjw1d6n"))))
+        (base32 "141jg70fim276i8k2kyypm84gy89i1k9mm4yf68mfwnybvjw1d6n"))
+       (patches (search-patches "esound-c99.patch"))))
     (build-system gnu-build-system)
     (native-inputs
      (list autoconf

gnu/packages/patches/esound-c99.patch

@@ -0,0 +1,19 @@
+Retrieved from: https://src.fedoraproject.org/rpms/esound/raw/rawhide/f/esound-c99.patch
+
+Declare clean_exit to avoid an implicit function declaration and
+future build breakage.  This style of declarations outside of header
+files is already used for other functions.
+
+diff --git a/clients.c b/clients.c
+index 1f7e4aa644bdc32c..14416e620dcccbbf 100644
+--- a/clients.c
++++ b/clients.c
+@@ -33,7 +33,7 @@ static int write_wait = 0;
+ /* prototypes */
+ void dump_clients(void);
+ void free_client( esd_client_t *client );
+-
++void clean_exit(int signum);
+ 
+ /*******************************************************************/
+ /* for debugging purposes, dump the list of the clients and data */