Fix some build warnings when building with musl

Makefile.am

@@ -15,7 +15,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 # USA.
 
-AM_CFLAGS = -Wall -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 @STATIC_CFLAGS@
+AM_CFLAGS = -Wall -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
 
 SUBDIRS=po
 
@@ -55,14 +55,11 @@ minidlnad_LDADD = \
 	@LIBID3TAG_LIBS@ \
 	@LIBSQLITE3_LIBS@ \
 	@LIBAVFORMAT_LIBS@ \
-	@LIBAVUTIL_LIBS@ \
 	@LIBEXIF_LIBS@ \
 	@LIBINTL@ \
 	@LIBICONV@ \
 	-lFLAC $(flacogglibs) $(vorbislibs) $(avahilibs)
 
-minidlnad_LDFLAGS = @STATIC_LDFLAGS@
-
 testupnpdescgen_SOURCES = testupnpdescgen.c upnpdescgen.c
 testupnpdescgen_LDADD = \
 	@LIBJPEG_LIBS@ \

configure.ac

@@ -69,6 +69,7 @@ AC_FUNC_FORK
 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
 AC_CHECK_FUNCS([gethostname getifaddrs gettimeofday inet_ntoa memmove memset mkdir realpath select sendfile setlocale socket strcasecmp strchr strdup strerror strncasecmp strpbrk strrchr strstr strtol strtoul])
 AC_CHECK_DECLS([SEEK_HOLE])
+AC_SEARCH_LIBS([clock_gettime], [rt], [AC_DEFINE([HAVE_CLOCK_GETTIME], [1], [use clock_gettime])],)
 
 #
 # Check for struct ip_mreqn
@@ -144,7 +145,6 @@ AC_COMPILE_IFELSE(
     ],
     [
         AC_MSG_RESULT([no])
-        AC_SEARCH_LIBS([clock_gettime], [rt], [AC_DEFINE([HAVE_CLOCK_GETTIME], [1], [use clock_gettime])],)
     ])
 
 AC_CHECK_HEADER(linux/netlink.h,
@@ -411,10 +411,10 @@ for dir in "" /usr/local $SEARCH_DIR; do
     if test -n "$dir"; then
         LDFLAGS="$LDFLAGS -L$dir/lib"
     fi
-    AC_CHECK_LIB([id3tag], [id3_file_open], [LIBID3TAG_LIBS="-lid3tag"], [unset ac_cv_lib_id3tag_id3_file_open; LDFLAGS="$LDFLAGS_SAVE"; continue])
+    AC_CHECK_LIB([id3tag -lz], [id3_file_open], [LIBID3TAG_LIBS="-lid3tag -lz"], [unset ac_cv_lib_id3tag_id3_file_open; LDFLAGS="$LDFLAGS_SAVE"; continue])
     break
 done
-test x"$ac_cv_lib_id3tag_id3_file_open" = x"yes" || AC_MSG_ERROR([Could not find libid3tag])
+test x"$ac_cv_lib_id3tag__lz___id3_file_open" = x"yes" || AC_MSG_ERROR([Could not find libid3tag])
 AC_SUBST(LIBID3TAG_LIBS)
 
 LDFLAGS_SAVE="$LDFLAGS"
@@ -435,20 +435,17 @@ for dir in "" /usr/local $SEARCH_DIR; do
     if test -n "$dir"; then
         LDFLAGS="$LDFLAGS -L$dir/lib"
     fi
-    AC_CHECK_LIB([avformat], [av_open_input_file], [LIBAVFORMAT_LIBS="-lavformat"],
+    AC_CHECK_LIB([avformat -lavcodec -lavutil -lz], [avformat_open_input], [LIBAVFORMAT_LIBS="-lavformat -lavcodec -lavutil -lz"],
-		 [AC_CHECK_LIB([avformat], [avformat_open_input], [LIBAVFORMAT_LIBS="-lavformat"],
+		 [AC_CHECK_LIB([avformat -lavcodec -lavutil -lz], [av_open_input_file], [LIBAVFORMAT_LIBS="-lavformat -lavcodec -lavutil -lz"],
 		  [unset ac_cv_lib_avformat_av_open_input_file; unset ac_cv_lib_avformat_avformat_open_input; LDFLAGS="$LDFLAGS_SAVE"; continue])])
     break
 done
-if test x"$ac_cv_lib_avformat_av_open_input_file" != x"yes" &&
+if test x"$ac_cv_lib_avformat__lavcodec__lavutil__lz___av_open_input_file" != x"yes" &&
-   test x"$ac_cv_lib_avformat_avformat_open_input" != x"yes"; then
+   test x"$ac_cv_lib_avformat__lavcodec__lavutil__lz___avformat_open_input" != x"yes"; then
    AC_MSG_ERROR([Could not find libavformat - part of ffmpeg])
 fi
 AC_SUBST(LIBAVFORMAT_LIBS)
 
-AC_CHECK_LIB(avutil ,[av_rescale_q], [LIBAVUTIL_LIBS="-lavutil"], [AC_MSG_ERROR([Could not find libavutil - part of ffmpeg])])
-AC_SUBST(LIBAVUTIL_LIBS)
-
 AC_CHECK_LIB(pthread, pthread_create)
 
 # test if we have vorbisfile
@@ -609,10 +606,22 @@ AC_MSG_CHECKING([whether to build a static binary executable])
 AC_ARG_ENABLE(static,
 	[  --enable-static         build a static binary executable],[
 	if test "$enableval" = "yes"; then
-		STATIC_CFLAGS="-DSTATIC"
+		CFLAGS="$CFLAGS -DSTATIC"
-		AC_SUBST(STATIC_CFLAGS)
+		LDFLAGS="$LDFLAGS -static"
-		STATIC_LDFLAGS="-Wl,-Bstatic"
+                AC_MSG_RESULT([yes])
-		AC_SUBST(STATIC_LDFLAGS)
+        else
+                AC_MSG_RESULT([no])
+        fi
+        ],[
+                AC_MSG_RESULT([no])
+        ]
+)
+
+AC_MSG_CHECKING([whether to enable LTO])
+AC_ARG_ENABLE(lto,
+	[  --enable-lto            enable link-time optimization],[
+	if test "$enableval" = "yes"; then
+		CFLAGS="$CFLAGS -flto"
                 AC_MSG_RESULT([yes])
         else
                 AC_MSG_RESULT([no])

image_utils.c

@@ -137,7 +137,7 @@ init_source(j_decompress_ptr cinfo)
 	return;
 }
 
-static int
+static boolean
 fill_input_buffer(j_decompress_ptr cinfo)
 {
 	struct my_src_mgr *src = (void *)cinfo->src;

upnphttp.c

@@ -1641,7 +1641,7 @@ SendResp_resizedimg(struct upnphttp * h, char * object)
 	char *resolution = NULL;
 	char *key, *val;
 	char *saveptr, *item = NULL;
-	int rotate;
+	int rotate = 0;
 	int pixw = 0, pixh = 0;
 	long long id;
 	int rows=0, chunked, ret;
@@ -1661,7 +1661,8 @@ SendResp_resizedimg(struct upnphttp * h, char * object)
 	{
 		file_path = result[3];
 		resolution = result[4];
-		rotate = result[5] ? atoi(result[5]) : 0;
+                if (result[5])
+			rotate = atoi(result[5]);
 	}
 	if( !file_path || !resolution || (access(file_path, F_OK) != 0) )
 	{