Use pkg-config to find gcrypt and libxml2.

Upstream-Status: Pending [libxml2 is upstreamable]

RP 2014/5/22

Index: libxslt-1.1.28/configure.in
===================================================================
--- libxslt-1.1.28.orig/configure.in	2014-05-13 16:46:02.278474967 +0000
+++ libxslt-1.1.28/configure.in	2014-05-13 16:53:56.510472561 +0000
@@ -376,6 +376,8 @@
 AC_SUBST(PYTHON_SUBDIR)
 AC_SUBST(PYTHON_LIBS)
 
+PKG_PROG_PKG_CONFIG
+
 AC_ARG_WITH(crypto, [  --with-crypto           Add crypto support to exslt (on)])
 WITH_CRYPTO=0
 if test "$with_crypto" = "no" ; then
@@ -391,26 +393,13 @@
     WITH_CRYPTO=1
     ;;
   *)
-    AC_PATH_PROG(LIBGCRYPT_CONFIG, libgcrypt-config, no)
-    if test "$LIBGCRYPT_CONFIG" != "no" ; then
-      LIBGCRYPT_VERSION=`$LIBGCRYPT_CONFIG --version`
-      if test VERSION_TO_NUMBER(echo $LIBGCRYPT_VERSION) -lt VERSION_TO_NUMBER(echo "1.1.42")
-      then
-        LIBGCRYPT_CFLAGS=""
-        LIBGCRYPT_LIBS=""
-        echo 'gcrypt library version < 1.1.42 - Crypto extensions will not be available.'
-      else
-        LIBGCRYPT_CFLAGS=`$LIBGCRYPT_CONFIG $libgcrypt_config_args --cflags`
-        LIBGCRYPT_LIBS=`$LIBGCRYPT_CONFIG $libgcrypt_config_args --libs`
-        AC_DEFINE(HAVE_GCRYPT, 1, [Define if gcrypt library is available.])
-        echo 'Crypto extensions will be available.'
+    PKG_CHECK_MODULES(LIBGCRYPT, [libgcrypt >= 1.1.42], [
+          AC_DEFINE(HAVE_GCRYPT, 1, [Define if gcrypt library is available.])
+          echo 'Crypto extensions will be available.'
 		WITH_CRYPTO=1
-      fi
-    else
-      LIBGCRYPT_CFLAGS=""
-      LIBGCRYPT_LIBS=""
-      echo 'Crypto extensions will not be available. Install libgcrypt and reconfigure to make available.'
-    fi
+	], [
+          echo 'Crypto extensions will not be available. Install libgcrypt >= 1.1.42 and reconfigure to make available.'
+        ])
 esac
 fi
 AC_SUBST(WITH_CRYPTO)
@@ -471,24 +460,8 @@
 dnl some tweaking - David Härdeman 30/10/2001
 dnl
 
-LIBXML_CONFIG_PREFIX=""
 LIBXML_SRC=""
 
-AC_ARG_WITH(libxml-prefix,
-        [  --with-libxml-prefix=[PFX]		Specify location of libxml config],
-	LIBXML_CONFIG_PREFIX=$withval
-)
-        
-AC_ARG_WITH(libxml-include-prefix,
-        [  --with-libxml-include-prefix=[PFX]	Specify location of libxml headers],
-        LIBXML_CFLAGS="-I$withval"
-)
-
-AC_ARG_WITH(libxml-libs-prefix,
-        [  --with-libxml-libs-prefix=[PFX]	Specify location of libxml libs],
-        LIBXML_LIBS="-L$withval"
-)
-
 AC_ARG_WITH(libxml-src,
 	[  --with-libxml-src=[DIR]              For libxml thats not installed yet (sets all three above)],
 	LIBXML_SRC="$withval"
@@ -551,28 +524,9 @@
 	fi
 fi
 
-dnl
-dnl make sure xml2-config is executable,
-dnl test version and init our variables
-dnl
-
-if ${XML_CONFIG} --libs print > /dev/null 2>&1
-then
-	XMLVERS=`$XML_CONFIG --version`
-	if test VERSION_TO_NUMBER(echo $XMLVERS) -ge VERSION_TO_NUMBER(echo $LIBXML_REQUIRED_VERSION)
-	then
-		AC_MSG_RESULT($XMLVERS found)
-	else
-		AC_MSG_ERROR(Version $XMLVERS found. You need at least libxml2 $LIBXML_REQUIRED_VERSION for this version of libxslt)
-	fi
-	LIBXML_LIBS="$LIBXML_LIBS `$XML_CONFIG --libs`"
-	if test "x$LIBXML_SRC" = "x"; then
-		LIBXML_CFLAGS="$LIBXML_CFLAGS `$XML_CONFIG --cflags`"
-	fi
-else
-	AC_MSG_ERROR([Could not find libxml2 anywhere, check ftp://xmlsoft.org/.])
-fi
-
+PKG_CHECK_MODULES(LIBXML, [libxml-2.0 >= $LIBXML_REQUIRED_VERSION],,
+    [AC_MSG_ERROR([Could not find libxml-2.0 >= $LIBXML_REQUIRED_VERSION anywhere, check ftp://xmlsoft.org/.])]
+)
 
 AC_SUBST(CFLAGS)
 AC_SUBST(CPPFLAGS)
@@ -597,7 +551,7 @@
 
 if test "$with_plugins" = "yes" ; then
   AC_MSG_CHECKING([libxml2 module support])
-  WITH_MODULES="`$XML_CONFIG --modules`"
+  WITH_MODULES="`$PKG_CONFIG --variable=modules libxml-2.0`"
   if test "${WITH_MODULES}" = "1"; then
     AC_MSG_RESULT(yes)
   else