Ensure versions.props contains sorted entries (like check-lib-versions did for ant).

build.gradle

@@ -42,6 +42,7 @@ apply from: file('gradle/validation/precommit.gradle')
 apply from: file('gradle/validation/forbidden-apis.gradle')
 apply from: file('gradle/validation/jar-checks.gradle')
 apply from: file('gradle/validation/git-status.gradle')
+apply from: file('gradle/validation/versions-props-sorted.gradle')
 
 // Additional development aids.
 apply from: file('gradle/maven/maven-local.gradle')

gradle/validation/versions-props-sorted.gradle

@@ -0,0 +1,19 @@
+// This ensures 'versions.props' file is sorted lexicographically.
+
+configure(rootProject) {
+  task versionsPropsAreSorted() {
+    doFirst {
+      def versionsProps = file('versions.props')
+      def lines = versionsProps.readLines("UTF-8")
+      def sorted = lines.toSorted()
+
+      if (!Objects.equals(lines, sorted)) {
+        def sortedFile = file("${buildDir}/versions.props")
+        sortedFile.write(sorted.join("\n"), "UTF-8")
+        throw new GradleException("${versionsProps} file is not sorted lexicographically. I wrote a sorted file to ${sortedFile} - please review and commit.")
+      }
+    }
+  }
+
+  precommit.dependsOn versionsPropsAreSorted
+}

versions.props

@@ -35,6 +35,7 @@ commons-logging:commons-logging=1.1.3
 de.l3s.boilerpipe:boilerpipe=1.1.0
 info.ganglia.gmetric4j:gmetric4j=1.0.7
 io.dropwizard.metrics:*=4.1.2
+io.jaegertracing:*=0.35.5
 io.netty:*=4.1.29.Final
 io.opentracing:*=0.33.0
 io.prometheus:*=0.2.0
@@ -107,5 +108,4 @@ org.slf4j:*=1.7.24
 org.tallison:jmatio=1.5
 org.tukaani:xz=1.8
 ua.net.nlp:morfologik-ukrainian-search=3.9.0
-xerces:xercesImpl=2.12.0
-io.jaegertracing:*=0.35.5
+xerces:xercesImpl=2.12.0