This patch eliminates the need for providing "xjavac", which saves building a
package for the unmaintained "xerces-tools".

Taken from https://anonscm.debian.org/viewvc/pkg-java/trunk/libxerces2-java/debian/patches/01_xjavac_taskdef.patch?revision=14507

Index: b/build.xml
===================================================================
--- a/build.xml
+++ b/build.xml
@@ -39,7 +39,7 @@
   <property name="tools.dir" value="./tools"/>
 
   <!-- enable compilation under JDK 1.4 and above -->
-  <taskdef name="xjavac" classname="org.apache.xerces.util.XJavac">
+  <taskdef name="xjavac" classname="org.apache.tools.ant.taskdefs.Javac">
     <classpath>
       <pathelement location="${tools.dir}/bin/xjavac.jar"/>
     </classpath>
@@ -291,7 +291,7 @@
            source="${javac.source}"
            target="${javac.target}"
            classpath="${build.dir}/classes:${tools.dir}/${jar.apis}:${tools.dir}/${jar.resolver}:${tools.dir}/${jar.serializer}"
-           debug="${debug}"
+           debug="${debug}" nowarn="true"
            debuglevel="${debuglevel}"
            deprecation="${deprecation}"
            optimize="${optimize}"
@@ -359,7 +359,7 @@
            source="${javac.source}"
            target="${javac.target}"
            classpath="${build.dir}/classes:${tools.dir}/${jar.apis}"
-           debug="${debug}"
+           debug="${debug}" nowarn="true"
            debuglevel="${debuglevel}"
            includeAntRuntime="false"
            includeJavaRuntime="true"/>
@@ -379,7 +379,7 @@
            source="${javac.source}"
            target="${javac.target}"
            classpath="${tools.dir}/${jar.apis}:${build.dir}/classes:./tools/junit.jar"
-           debug="${debug}"
+           debug="${debug}" nowarn="true"
            debuglevel="${debuglevel}"
            includeAntRuntime="false"
            includeJavaRuntime="true"/>
ut type='hidden' name='id' value='820bf78cbc487d28457acc6cb790f4cbd7cc49b9'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=820bf78cbc487d28457acc6cb790f4cbd7cc49b9'>root</a>/<a href='/guix/log/gnu?id=820bf78cbc487d28457acc6cb790f4cbd7cc49b9'>gnu</a>/<a href='/guix/log/gnu/packages?id=820bf78cbc487d28457acc6cb790f4cbd7cc49b9'>packages</a>/<a href='/guix/log/gnu/packages/patches?id=820bf78cbc487d28457acc6cb790f4cbd7cc49b9'>patches</a>/<a href='/guix/log/gnu/packages/patches/mixxx-link-qtscriptbytearray-qtscript.patch?id=820bf78cbc487d28457acc6cb790f4cbd7cc49b9'>mixxx-link-qtscriptbytearray-qtscript.patch</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/patches/mixxx-link-qtscriptbytearray-qtscript.patch?id=820bf78cbc487d28457acc6cb790f4cbd7cc49b9&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-10-16 17:32:25 -0400'>2021-10-16</span></td><td><a href='/guix/commit/gnu/packages/patches/mixxx-link-qtscriptbytearray-qtscript.patch?id=8c55fdf80a03098f5acc71eab76d89e3feb2c222'>gnu: Add mixxx.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/music.scm (mixxx): New variable.
* gnu/packages/patches/mixxx-link-qtscriptbytearray-qtscript.patch,
gnu/packages/patches/mixxx-system-googletest-benchmark.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.

Signed-off-by: Leo Famulari &lt;leo@famulari.name&gt;
</span></span></td><td>Vinicius Monego</td></tr>
u/packages/patches/unzip-fix-recmatch.patch,
gnu/packages/patches/unzip-manpage-fix.patch,
gnu/packages/patches/unzip-overflow.patch,
gnu/packages/patches/unzip-symlink.patch,
gnu/packages/patches/unzip-timestamp.patch,
gnu/packages/patches/unzip-valgrind.patch,
gnu/packages/patches/unzip-x-option.patch,
gnu/packages/patches/unzip-zipbomb-manpage.patch,
gnu/packages/patches/unzip-zipbomb-part1.patch,
gnu/packages/patches/unzip-zipbomb-part2.patch,
gnu/packages/patches/unzip-zipbomb-part3.patch: New patches.
* gnu/local.mk (dist_patch_DATA): Register them.
* gnu/packages/compression.scm (unzip/fixed): New variable. Apply patches.
(unzip)[replacement]: Graft.
</span></span></td><td>Léo Le Bouter</td></tr>