Fix test suite for compatibility with Solr 9.1. (vufind-org#42)

- Works around test suite bug introduced in Solr 9.1 (see SOLR-16553)
- Makes sure build fails when tests fail

build.xml

@@ -10,6 +10,9 @@
   <property name="vufind.dir" value="/usr/local/vufind"/>
   <property name="absolute.vufind.dir" location="${vufind.dir}"/>
   <property name="solr.solr.home" value="${absolute.vufind.dir}/solr/vufind"/>
+  <!-- The solr.install.dir property was added to work around an issue in the Solr 9.1 test suite;
+       it can probably be safely removed once VuFind upgrades to Solr 9.2 or higher. -->
+  <property name="solr.install.dir" value="${absolute.vufind.dir}/solr/vendor"/>
   <property name="java.compat.version" value="1.8"/>
   <property name="ant.build.javac.source" value="1.8"/>
   <property name="ant.build.javac.target" value="1.8"/>
@@ -22,6 +25,9 @@
     <fileset dir="libs">
       <include name="**/*.jar"/>
     </fileset>
+    <fileset dir="tests/lib">
+      <include name="**/*.jar"/>
+    </fileset>
     <!-- For Solr 8 and below: -->
     <fileset erroronmissingdir="false" dir="${absolute.vufind.dir}/solr/vendor/contrib/analysis-extras">
       <include name="**/*.jar"/>
@@ -202,9 +208,10 @@
         <compilerarg line="-encoding UTF-8" />
       </javac>
 
-      <junit showoutput="yes" fork="true">
+      <junit showoutput="yes" fork="true" haltonfailure="on">
         <sysproperty key="absolute.vufind.dir" value="${absolute.vufind.dir}" />
         <sysproperty key="solr.solr.home" value="${solr.solr.home}" />
+        <sysproperty key="solr.install.dir" value="${solr.install.dir}" />
         <jvmarg value="-Dfile.encoding=UTF-8" />
         <classpath>
           <pathelement location="tests/lib/junit-4.11.jar"/>