MINOR: Set the POM SCM tag when preparing and publishing releases

release/bin/prepare-rc.sh

@@ -221,33 +221,57 @@ step_summary "> it is a mechanical version bump on top of the verified"
 step_summary "> commit above."
 
 # ---------------------------------------------------------------------------
-# Step 4: Set POM versions (only on rc0 or if version doesn't match)
+# Step 4: Set POM version and SCM tag (whenever either doesn't match)
 # ---------------------------------------------------------------------------
 step_summary ""
 step_summary "### Version Update"
 
 current_pom_version=$(get_current_pom_version || echo "unknown")
+current_scm_tag=$(get_current_pom_scm_tag || echo "unknown")
 print_info "Current POM version: ${current_pom_version}"
+print_info "Current POM SCM tag: ${current_scm_tag}"
 
-if [[ "${current_pom_version}" == "${version}" ]]; then
-  print_info "POM version already set to ${version}, skipping version update"
-  step_summary "POM version already at \`${version}\`, no update needed"
+if [[ "${current_pom_version}" == "${version}" && "${current_scm_tag}" == "${rc_tag}" ]]; then
+  print_info "POM version and SCM tag already set for ${rc_tag}, skipping update"
+  step_summary "POM version already at \`${version}\` and SCM tag at \`${rc_tag}\`, no update needed"
 else
-  print_info "Setting POM version to ${version}..."
-  set_pom_version "${version}"
-  step_summary "Updated POM version: \`${current_pom_version}\` -> \`${version}\`"
+  if [[ "${current_pom_version}" != "${version}" ]]; then
+    print_info "Setting POM version to ${version}..."
+    set_pom_version "${version}"
+    step_summary "Updated POM version: \`${current_pom_version}\` -> \`${version}\`"
+  fi
+
+  # Each RC needs its own tag here, so this also runs on rc1+ when the
+  # version is already set. Whatever the branch carried is overwritten.
+  if [[ "${current_scm_tag}" != "${rc_tag}" ]]; then
+    print_info "Setting POM SCM tag to ${rc_tag}..."
+    set_pom_scm_tag "${rc_tag}"
+    step_summary "Updated POM SCM tag: \`${current_scm_tag}\` -> \`${rc_tag}\`"
+  fi
 
-  # Commit version changes. Stage tracked files only: set_pom_version only
-  # edits existing POMs, and anything untracked must not land in the release.
+  # Commit version changes. Stage tracked files only: the version and SCM tag
+  # updates only edit existing POMs, and anything untracked must not land in
+  # the release.
   exec_process git add -u
-  exec_process git commit -m "Set version to ${version} for release"
+  exec_process git commit -m "Set version to ${version} for release (${rc_tag})"
 fi
 
 if ! require_clean_worktree; then
   step_summary "Working tree check: **FAILED** (see the job log for the offending paths)"
   exit 1
 fi
 
+# The staged POMs are what Maven Central publishes, so refuse to tag and
+# deploy a commit whose <scm><tag> doesn't name this RC.
+if [[ ${DRY_RUN:-1} -ne 1 ]]; then
+  committed_scm_tag=$(get_current_pom_scm_tag || echo "unknown")
+  if [[ "${committed_scm_tag}" != "${rc_tag}" ]]; then
+    print_error "POM SCM tag is '${committed_scm_tag}', expected '${rc_tag}'"
+    step_summary "SCM tag check: **FAILED** (\`${committed_scm_tag}\` != \`${rc_tag}\`)"
+    exit 1
+  fi
+fi
+
 # ---------------------------------------------------------------------------
 # Step 5: Create RC tag locally (pushed in step 9)
 # ---------------------------------------------------------------------------

release/bin/publish-release.sh

@@ -176,6 +176,18 @@ if ! git rev-parse "${rc_tag}" >/dev/null 2>&1; then
   exit 1
 fi
 
+# The workflow is dispatched from master, which is where these scripts live,
+# so switch to the release branch before comparing it with the RC tag. This
+# runs in dry-run mode too: it is local, and the checks below depend on it.
+release_branch="${BRANCH_PREFIX}${major}.${minor}.x"
+if [[ "$(git branch --show-current)" != "${release_branch}" ]]; then
+  print_info "Switching to ${release_branch}..."
+  if ! git checkout "${release_branch}"; then
+    print_error "Could not check out release branch ${release_branch}"
+    exit 1
+  fi
+fi
+
 rc_commit=$(git rev-list -1 "${rc_tag}")
 current_commit=$(git rev-parse HEAD)
 
@@ -314,6 +326,7 @@ next_snapshot="${next_dev_version}-SNAPSHOT"
 print_info "Bumping version to ${next_snapshot}..."
 
 set_pom_version "${next_snapshot}"
+set_pom_scm_tag "HEAD"
 
 # Update previous.version property
 exec_process ./mvnw -pl . versions:set-property \
@@ -333,7 +346,7 @@ expected_branch="${BRANCH_PREFIX}${major}.${minor}.x"
 if [[ "${current_branch}" != "${expected_branch}" ]]; then
   print_error "Refusing to push version bump: current branch is '${current_branch}'"
   print_error "Expected to be on release branch '${expected_branch}' for version ${version}."
-  print_error "Run the publish workflow with that branch selected, or check out '${expected_branch}' locally."
+  print_error "The script checks out '${expected_branch}' before publishing; something switched branches since then."
   exit 1
 fi
 # Also confirm the format independently in case someone has named a

release/libs/_version.sh

@@ -91,3 +91,13 @@ function set_pom_version {
 function get_current_pom_version {
   ./mvnw help:evaluate -Dexpression=project.version -q -DforceStdout 2>/dev/null
 }
+
+# Only the root POM declares <scm>; every module inherits its tag.
+function set_pom_scm_tag {
+  local tag="$1"
+  exec_process ./mvnw -pl . versions:set-scm-tag -DnewTag="${tag}" -DgenerateBackupPoms=false --batch-mode -q
+}
+
+function get_current_pom_scm_tag {
+  ./mvnw -pl . help:evaluate -Dexpression=project.scm.tag -q -DforceStdout 2>/dev/null
+}

release/tests/version.bats

@@ -175,6 +175,43 @@ setup() {
   [[ "$output" == *"2.0.0-SNAPSHOT"* ]]
 }
 
+# ---- set_pom_scm_tag ----
+
+@test "set_pom_scm_tag: passes correct args to mvnw in dry-run" {
+  DRY_RUN=1
+  run set_pom_scm_tag "apache-parquet-1.18.2-rc1"
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"-pl . versions:set-scm-tag"* ]]
+  [[ "$output" == *"-DnewTag=apache-parquet-1.18.2-rc1"* ]]
+  [[ "$output" == *"-DgenerateBackupPoms=false"* ]]
+}
+
+@test "set_pom_scm_tag: accepts HEAD for the next development iteration" {
+  DRY_RUN=1
+  run set_pom_scm_tag "HEAD"
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"-DnewTag=HEAD"* ]]
+}
+
+# ---- get_current_pom_scm_tag ----
+
+@test "get_current_pom_scm_tag: evaluates project.scm.tag on the root POM" {
+  local tmpbin
+  tmpbin=$(mktemp -d)
+  cat > "${tmpbin}/mvnw" << 'SCRIPT'
+#!/bin/bash
+if [[ "$*" == *"-pl . help:evaluate -Dexpression=project.scm.tag"* ]]; then
+  echo "apache-parquet-1.18.0-rc2"
+fi
+SCRIPT
+  chmod +x "${tmpbin}/mvnw"
+  cd "${tmpbin}"
+  local result
+  result=$(get_current_pom_scm_tag)
+  [ "$result" = "apache-parquet-1.18.0-rc2" ]
+  rm -rf "${tmpbin}"
+}
+
 # ---- find_latest_rc_number ----
 
 @test "find_latest_rc_number: returns highest RC number" {