[Jenkins-Build] Migrate push steps from ANT to Jenkins pipeline

This also has the advantage that for commits pushed to maintenance
branches, the follow-up commits created by the build pipeline are pushed
to the same branch automatically.

Author: HannesWell

Jenkinsfile

@@ -316,21 +316,29 @@ pipeline {
 			}
 			steps {
 				sshagent(['github-bot-ssh']) {
-					withAnt(installation: 'apache-ant-latest', jdk: 'openjdk-jdk11-latest') { // nashorn javascript-engine required in ant-scripts
+					script {
+						def swtNativesTag = null;
+						dir ('eclipse.platform.swt.binaries') {
+							swtNativesTag = sh(script: 'git describe --abbrev=0 --tags --match v[0-9][0-9][0-9][0-9]*', returnStdout: true).strip()
+						}
+						echo "swtNativesTag: ${swtNativesTag}"
 						sh '''
 							# Check for the master-branch as late as possible to have as much of the same behaviour as possible
 							if [[ "${BRANCH_NAME}" == master ]] || [[ "${BRANCH_NAME}" =~ R[0-9]+_[0-9]+(_[0-9]+)?_maintenance ]]; then
 								if [[ ${skipCommit} != true ]]; then
 									
+									#Don't rebase and just fail in case another commit has been pushed to the master/maintanance branch in the meantime
+									
 									pushd eclipse.platform.swt
-									git fetch origin refs/heads/${BRANCH_NAME}:refs/remotes/origin/${BRANCH_NAME}
+									git push origin HEAD:refs/heads/${BRANCH_NAME}
+									git push origin refs/tags/${swtNativesTag}
 									popd
 									
 									pushd eclipse.platform.swt.binaries
-									git fetch origin refs/heads/${BRANCH_NAME}:refs/remotes/origin/${BRANCH_NAME}
+									git push origin HEAD:refs/heads/${BRANCH_NAME}
+									git push origin refs/tags/${swtNativesTag}
 									popd
 									
-									ant -f eclipse.platform.swt/bundles/org.eclipse.swt/buildSWT.xml push_remote_from_workspace
 									exit 0
 								else
 									echo Committing is skipped

bundles/org.eclipse.swt/buildSWT.xml

@@ -963,39 +963,6 @@
 	<!-- targets to run the builds on the Eclipse Foundation Hudson in master-slave setup -->
 	<!-- ******************************************************************************** -->
 
-	<target name="push_remote_from_workspace" depends="get_tag">
-		<exec dir="${repo.src}" executable="git" failonerror="true">
-			<arg line="fetch"/>
-		</exec>
-		<exec dir="${repo.src}" executable="git" failonerror="true">
-			<arg line="status"/>
-		</exec>
-		<exec dir="${repo.src}" executable="git" failonerror="true">
-			<arg line="rebase origin/${TAG}"/>
-		</exec>
-		<exec dir="${repo.src}" executable="git" failonerror="true">
-			<arg line="push origin HEAD:refs/heads/${TAG}"/>
-		</exec>
-		<exec dir="${repo.bin}" executable="git" failonerror="true">
-			<arg line="fetch"/>
-		</exec>
-		<exec dir="${repo.bin}" executable="git" failonerror="true">
-			<arg line="status"/>
-		</exec>
-		<exec dir="${repo.bin}" executable="git" failonerror="true">
-			<arg line="rebase origin/${TAG}"/>
-		</exec>
-		<exec dir="${repo.bin}" executable="git" failonerror="true">
-			<arg line="push origin HEAD:refs/heads/${TAG}"/>
-		</exec>
-		<exec dir="${repo.src}" executable="git" failonerror="true">
-			<arg line="push origin refs/tags/${swt_tag}"/>
-		</exec>
-		<exec dir="${repo.bin}" executable="git" failonerror="true">
-			<arg line="push origin refs/tags/${swt_tag}"/>
-		</exec>
-	</target>
-	
 	<target name="new_build_with_create_file" depends="check_build_changed, check_natives_changed" if="build_changed">
 		<!-- Update the version files -->
 		<property name="increment_version_target" value="increment_version"/>