Modified handling of version.properties generation.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/FOP_0-20-0_Alt-Design@197094 13f79535-47bb-0310-9956-ffa450edef68

build.xml

@@ -170,6 +170,10 @@ list of possible build targets.
     <property name="NAME" value="FOP"/>
     <property name="year" value="1999-2003"/>
 
+    <property name="fop.dir" value="org/apache/fop"/>
+    <property name="packages" value="org.apache.fop.*"/>
+    <property name="fop.prefix" value="org.apache.fop"/>
+
     <!-- Compilation parameters -->
     <property name="debug" value="on"/>
     <property name="optimize" value="off"/>
@@ -183,15 +187,6 @@ list of possible build targets.
     <property name="hyph.dir" value="${src.dir}/hyph"/>
     <property name="conf.dir" value="${basedir}/conf"/>
 
-    <!-- Properties for derivation of Version information -->
-    <property name="fop.dir" value="org/apache/fop"/>
-    <property name="version.dir" value="${fop.dir}/version"/>
-    <property name="version.src.java" value="${src.java}/${version.dir}"/>
-
-    <property name="packages" value="org.apache.fop.*"/>
-    <property name="fop.prefix" value="org.apache.fop"/>
-    <property name="version.prefix" value="${fop.prefix}.version"/>
-
     <!-- Font generation properties -->
     <property name="fonts.dir" value="${fop.dir}/fonts"/>
     <property name="base14.dir" value="${fonts.dir}/base14"/>
@@ -225,6 +220,19 @@ list of possible build targets.
     <property name="build.examples.test.dir"
                                   value="${build.fo.examples.dir}"/>
 
+    <!-- Properties for derivation of Version information -->
+    <property name="version.dir" value="${fop.dir}/version"/>
+    <property name="version.src.dir" value="${src.java}/${version.dir}"/>
+    <property name="version.src.name" value="Version.java"/>
+    <property name="version.src.file" value="${version.src.dir}/${version.src.name}"/>
+    <property name="version.class.dir" value="${build.dest}/${version.dir}"/>
+    <property name="version.class.name" value="Version.class"/>
+    <property name="version.class" value="${version.class.dir}/${version.class.name}"/>
+    <property name="version.prefix" value="${fop.prefix}.version"/>
+    <property name="tmp.version.dir" value="${build.tmp}"/>
+    <property name="tmp.version.filename" value="version.property"/>
+    <property name="tmp.version.file" value="${build.tmp}/${tmp.version.filename}"/>
+
   </target>
 
   <!-- =================================================================== -->
@@ -245,18 +253,35 @@ list of possible build targets.
   <!-- =================================================================== -->
   <!-- Generate the build version properties                               -->
   <!-- =================================================================== -->
-  <target name="version" depends="makedirs">
+  <target name="version-properties" depends="makedirs">
+    <dependset>
+      <srcfilelist dir="${version.class.dir}" files="${version.class.name}"/>
+      <srcfilelist dir="${version.src.dir}" files="${version.src.name}"/>
+      <targetfilelist
+          dir="${tmp.version.dir}" files="${tmp.version.filename}"/>
+    </dependset>
+    <condition property="tmp.version.available">
+      <available file="${tmp.version.file}"/>
+    </condition>
+  </target>
+
+
+  <!-- =================================================================== -->
+  <!-- Generate the build version properties                               -->
+  <!-- =================================================================== -->
+  <target name="version"
+      depends="version-properties" unless="tmp.version.available">
 
     <!-- Compile Version.java if necessary -->
     <echo message="Check for current Version class file."/>
-    <property name="tmp.version.file" value="${build.tmp}/version.property"/>
-    <javac srcdir="${version.src.java}" destdir="${build.dest}"
+    <javac srcdir="${version.src.dir}" destdir="${build.dest}"
             debug="${debug}" deprecation="${deprecation}"
             optimize="${optimize}"/>
 
     <!-- Run Version.class and capture output, which defines properties
             "build.description" and "build.tag"
             or "build.default.description" and "build.default.tag". -->
+    <echo message="Generate version properties file."/>
     <java classname="org.apache.fop.version.Version"
             failonerror="true" output="${tmp.version.file}">
       <classpath location="${build.dest}"/>