log4c: fix undeclared dependency on expat

The original log4c configure.in is buggy and requires fixing
before "configure --with-expat" works as expected.

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

meta-oe/recipes-support/log4c/log4c/fix_configure_with-expat.patch

@@ -0,0 +1,21 @@
+The original use of AC_ARG_WITH is buggy and causes expat support
+to be *disabled* if "--with-expat" is passed to configure.
+
+Upstream status: pending
+
+Index: log4c-1.2.4/configure.in
+===================================================================
+--- log4c-1.2.4.orig/configure.in
++++ log4c-1.2.4/configure.in
+@@ -217,9 +217,9 @@ AC_ARG_WITH(expat,
+                     have any effect and Log4C uses some bundled yacc/lex code
+                     for parsing it's configuration file.
+                     ]),
+-                    with_expat=no,
++                    [],
+                     with_expat=yes)
+-if test x$with_expat = xyes ; then
++if test x$with_expat != xno ; then
+  use_expat=yes
+  AM_PATH_EXPAT(1.95.1)
+ fi

meta-oe/recipes-support/log4c/log4c_1.2.4.bb

@@ -1,16 +1,15 @@
-SUMMARY = "Logging Framework for C"
+SUMMARY = "Log4c is a C library for flexible logging to files, syslog and other destinations"
 HOMEPAGE = "http://log4c.sourceforge.net"
 LICENSE = "LGPLv2"
-
 LIC_FILES_CHKSUM = "file://COPYING;md5=4fbd65380cdd255951079008b364516c"
 
-SRC_URI = "http://cznic.dl.sourceforge.net/project/log4c/log4c/${PV}/log4c-${PV}.tar.gz"
+SRC_URI = "${SOURCEFORGE_MIRROR}/${BPN}/${BP}.tar.gz \
+           file://fix_configure_with-expat.patch"
+
 SRC_URI[md5sum] = "0d94919136e1d16b68427562e74cb3dd"
 SRC_URI[sha256sum] = "5991020192f52cc40fa852fbf6bbf5bd5db5d5d00aa9905c67f6f0eadeed48ea"
 
-S = "${WORKDIR}/${PN}-${PV}"
-
-EXTRA_OECONF = "--prefix=/usr"
+PACKAGECONFIG ??= "expat"
+PACKAGECONFIG[expat] = "--with-expat,--without-expat,expat"
 
 inherit autotools
-