[STC-767] Release old semantic identifiers

https://community.openproject.org/wp/STC-767

app/components/admin/settings/project_reserved_identifiers/release_dialog_component.html.erb

@@ -33,6 +33,10 @@
   render(
     Primer::OpenProject::DangerDialog.new(
       id: "release-identifier-dialog",
+      # The default :medium size caps the dialog height at 320px, which the
+      # description with the work package count can exceed, forcing an inner
+      # scrollbar. :medium_portrait keeps the same width with a 600px cap.
+      size: :medium_portrait,
       title: I18n.t("admin.reserved_identifiers.dialog.title"),
       confirm_button_text: I18n.t("admin.reserved_identifiers.dialog.confirm_button"),
       cancel_button_text: I18n.t("button_cancel"),
@@ -47,9 +51,7 @@
         I18n.t("admin.reserved_identifiers.dialog.heading", identifier: @slug.slug)
       end
 
-      message.with_description_content(
-        I18n.t("admin.reserved_identifiers.dialog.description")
-      )
+      message.with_description_content(description_text)
     end
 
     dialog.with_confirmation_check_box_content(

app/components/admin/settings/project_reserved_identifiers/release_dialog_component.rb

@@ -39,6 +39,21 @@ module Admin
           super
           @slug = slug
         end
+
+        private
+
+        def description_text
+          if affected_work_package_count.positive?
+            I18n.t("admin.reserved_identifiers.dialog.description_with_work_packages",
+                   count: affected_work_package_count)
+          else
+            I18n.t("admin.reserved_identifiers.dialog.description")
+          end
+        end
+
+        def affected_work_package_count
+          @affected_work_package_count ||= WorkPackage.resolving_via_slug_prefix(@slug.slug).count
+        end
       end
     end
   end

app/controllers/admin/settings/project_reserved_identifiers_controller.rb

@@ -34,7 +34,6 @@ module Admin::Settings
     include PaginationHelper
 
     before_action :require_admin
-    before_action :require_classic_mode
     before_action :find_slug, only: %i[confirm_dialog destroy]
 
     menu_item :project_reserved_identifiers_settings
@@ -63,7 +62,7 @@ module Admin::Settings
     end
 
     def destroy
-      @slug.destroy!
+      ProjectIdentifiers::ReleaseReservedIdentifierService.new(@slug).call
       redirect_to admin_settings_project_reserved_identifiers_path,
                   flash: { notice: t("admin.reserved_identifiers.released_notice", identifier: @slug.slug) }
     end
@@ -85,12 +84,5 @@ module Admin::Settings
              query_class: Queries::ProjectReservedIdentifiers::ProjectReservedIdentifierQuery)
         .call(params)
     end
-
-    def require_classic_mode
-      return unless Setting::WorkPackageIdentifier.semantic?
-
-      redirect_to admin_settings_work_packages_identifier_path,
-                  flash: { warning: t("admin.reserved_identifiers.not_available_in_semantic_mode") }
-    end
   end
 end

app/models/queries/project_reserved_identifiers/project_reserved_identifier_query.rb

@@ -37,9 +37,15 @@ class Queries::ProjectReservedIdentifiers::ProjectReservedIdentifierQuery
   end
 
   def default_scope
+    # Pure-numeric slugs are legacy artifacts (identifier validation was tightened
+    # later; the semantic-conversion autofix renames such projects, reserving the
+    # old numeric identifier). Releasing them frees nothing — numeric identifiers
+    # are invalid in both formats — and would break friendly_id history resolution
+    # of old /projects/<number> links, letting them fall through to a primary-key
+    # lookup of a different project.
     Project.identifier_slugs
       .historically_reserved
-      .where("slug ~ ? AND slug !~ ?", "^[a-z0-9_-]+$", "^[0-9]+$")
+      .where("slug !~ ?", "^[0-9]+$")
       .joins("JOIN projects ON projects.id = friendly_id_slugs.sluggable_id")
       .order("projects.name ASC, friendly_id_slugs.created_at DESC")
   end

app/models/work_package/semantic_identifier.rb

@@ -41,6 +41,16 @@ module WorkPackage::SemanticIdentifier
   # The frontend equivalent lives in WP_ID_URL_PATTERN (work-package-id-pattern.ts).
   ID_ROUTE_CONSTRAINT = /\d+|#{SEMANTIC_ID_PATTERN.source}/
 
+  # Anchored POSIX regex matching identifiers of the exact form "<slug>-<digits>"
+  # for a concrete project slug, so prefixes containing dashes don't over-match
+  # (matching "my" must not touch "my-project-42"). Used by the for_slug_prefix
+  # scopes on WorkPackage and WorkPackageSemanticAlias. Regexp.escape output is
+  # valid in PostgreSQL's ARE syntax: it backslash-escapes punctuation (which
+  # ARE treats as literals) and never emits class escapes.
+  def self.slug_prefix_pattern(slug)
+    "^#{Regexp.escape(slug)}-[0-9]+$"
+  end
+
   # Raised when a finder is invoked in a way that cannot resolve a semantic
   # identifier — e.g. find_by(id: "PROJ-42") which reduces to a raw SQL
   # WHERE clause that cannot consult the alias table. Subclasses ArgumentError
@@ -64,6 +74,21 @@ module WorkPackage::SemanticIdentifier
       joins(:project).semantically_sequenced
         .where("work_packages.identifier IS DISTINCT FROM projects.identifier || '-' || work_packages.sequence_number::text")
     }
+    # Work packages whose identifier column carries the given project slug
+    # prefix, i.e. is of the exact form "<slug>-<digits>". Counterpart to
+    # WorkPackageSemanticAlias.for_slug_prefix for the denormalized column.
+    scope :for_slug_prefix, ->(slug) {
+      where("identifier ~ ?", WorkPackage::SemanticIdentifier.slug_prefix_pattern(slug))
+    }
+    # Work packages that currently resolve via identifiers of the form
+    # "<slug>-<digits>" — through the identifier column or an alias row.
+    # The single-identifier counterpart is FinderMethods#scope_for_semantic_identifier.
+    # ReleaseReservedIdentifierService severs exactly this set, and the release
+    # dialog counts it — keep the two in sync through this scope.
+    scope :resolving_via_slug_prefix, ->(slug) {
+      where(id: WorkPackageSemanticAlias.for_slug_prefix(slug).select(:work_package_id))
+        .or(for_slug_prefix(slug))
+    }
 
     attr_accessor :skip_semantic_id_allocation
 

app/models/work_package_semantic_alias.rb

@@ -42,4 +42,12 @@ class WorkPackageSemanticAlias < ApplicationRecord
 
   validates :identifier, presence: true, uniqueness: true
   validates :work_package, presence: true
+
+  # Aliases created for the given project slug prefix, i.e. identifiers of the
+  # exact form "<slug>-<digits>". Case-sensitive: aliases are always created
+  # verbatim from slug values, and slugs differing only in case (classic "proj"
+  # vs semantic "PROJ") are distinct reservations.
+  scope :for_slug_prefix, ->(slug) {
+    where("identifier ~ ?", WorkPackage::SemanticIdentifier.slug_prefix_pattern(slug))
+  }
 end

app/services/project_identifiers/release_reserved_identifier_service.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+module ProjectIdentifiers
+  # Releases a historically reserved project identifier slug.
+  # Additionally removes the WorkPackageSemanticAlias rows created for that
+  # slug prefix ("<slug>-<digits>") and clears stale work package identifier
+  # columns carrying it, atomically with the slug destroy, so the released
+  # prefix no longer resolves work packages. This happens regardless of the
+  # current identifier mode: leftovers from a previous semantic phase must not
+  # survive a release, or they would keep old links resolving and shadow the
+  # alias rows of a new project claiming the identifier after a later
+  # re-conversion.
+  class ReleaseReservedIdentifierService
+    def initialize(slug)
+      @slug = slug
+    end
+
+    def call
+      FriendlyId::Slug.transaction do
+        delete_aliases
+        clear_stale_work_package_identifiers
+        @slug.destroy!
+      end
+
+      ServiceResult.success
+    end
+
+    private
+
+    def delete_aliases
+      WorkPackageSemanticAlias.for_slug_prefix(@slug.slug).delete_all
+    end
+
+    # A historically reserved slug is no project's current identifier, so any
+    # work package still carrying "<slug>-<digits>" in its identifier column is
+    # stale (left over from a revert to classic mode). The finder resolves
+    # semantic identifiers against this column as well as the alias table, so
+    # clearing it severs resolution immediately instead of waiting for the next
+    # semantic conversion's reset_stale_identifiers to do the same.
+    def clear_stale_work_package_identifiers
+      WorkPackage.for_slug_prefix(@slug.slug).update_all(identifier: nil, sequence_number: nil)
+    end
+  end
+end

config/initializers/menus.rb

@@ -464,7 +464,7 @@ Redmine::MenuManager.map :admin_menu do |menu|
 
   menu.push :project_reserved_identifiers_settings,
             { controller: "/admin/settings/project_reserved_identifiers", action: :index },
-            if: ->(_) { User.current.admin? && Setting::WorkPackageIdentifier.classic? },
+            if: ->(_) { User.current.admin? },
             caption: :label_reserved_identifiers,
             parent: :admin_projects_settings
 

config/locales/en.yml

@@ -61,25 +61,27 @@ en:
 
   admin:
     reserved_identifiers:
-      title: "Reserved project identifiers"
-      lede_html: "When a project's identifier is renamed, the previous identifier is kept reserved so that existing links and integrations keep working.<br>Here you can release reserved identifiers so that they may be used by other projects."
+      btn_release: "Unreserve"
       col_identifier: "Identifier"
       col_project: "Project"
       col_reserved: "Reserved"
-      not_available_in_semantic_mode: "Reserved project identifiers are only available in numeric identifier mode."
-      filter_label: "Search identifiers"
-      btn_release: "Release"
-      released_notice: 'Identifier "%{identifier}" has been released.'
-      identifier_not_found: "The reserved identifier could not be found. It may have already been released or the project may have been deleted. Please refresh the page."
       dialog:
-        title: "Release identifier"
-        heading: 'Release "%{identifier}"?'
-        description: "Releasing this identifier cannot be undone. External links and integrations using it will stop resolving, and the name becomes available for any new project to claim."
         checkbox_label: "I understand that this cannot be undone."
-        confirm_button: "Release identifier"
+        confirm_button: "Unreserve identifier"
+        description: "Unreserving this project identifier cannot be undone. External links and integrations using it will stop resolving, and the name becomes available for any new project to claim."
+        description_with_work_packages:
+          one: "Unreserving this project identifier (and its 1 work package identifier) cannot be undone. External links and integrations using it will stop resolving, and the name becomes available for any new project to claim."
+          other: "Unreserving this project identifier (and its %{count} work package identifiers) cannot be undone. External links and integrations using it will stop resolving, and the name becomes available for any new project to claim."
+        heading: 'Unreserve "%{identifier}"?'
+        title: "Unreserve identifier"
+      empty_body: "When a project's identifier changes, the previous one will appear here so you can unreserve it once it's safe to do so."
       empty_heading: "No reserved identifiers"
+      filter_label: "Search identifiers"
+      identifier_not_found: "The reserved identifier could not be found. It may have already been unreserved or the project may have been deleted. Please refresh the page."
+      lede_html: "When a project's identifier is renamed, the previous identifier is kept reserved so that existing links and integrations keep working.<br>Here you can unreserve identifiers so that they may be used by other projects."
+      released_notice: 'Identifier "%{identifier}" has been unreserved.'
       reserved_ago: "%{time} ago"
-      empty_body: "When a project's identifier changes, the previous one will appear here so you can release it once it's safe to do so."
+      title: "Reserved project identifiers"
     plugins:
       no_results_title_text: There are currently no plugins installed.
       no_results_content_text: See our integrations and plugins page for more information.

spec/components/admin/settings/project_reserved_identifiers/release_dialog_component_spec.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "rails_helper"
+
+RSpec.describe Admin::Settings::ProjectReservedIdentifiers::ReleaseDialogComponent, type: :component do
+  let!(:project) { create(:project) }
+  let!(:slug) { FriendlyId::Slug.create!(sluggable: project, slug: "old-id") }
+
+  subject(:rendered_component) { render_inline(described_class.new(slug:)) }
+
+  it "renders the heading with the identifier" do
+    expect(rendered_component)
+      .to have_text(I18n.t("admin.reserved_identifiers.dialog.heading", identifier: "old-id"))
+  end
+
+  context "without affected work packages" do
+    it "renders the plain description" do
+      expect(rendered_component)
+        .to have_text(I18n.t("admin.reserved_identifiers.dialog.description"))
+      expect(rendered_component).to have_no_text("work package")
+    end
+  end
+
+  context "with one affected work package" do
+    before { create(:work_package_semantic_alias, identifier: "old-id-1") }
+
+    it "renders the singular description" do
+      expect(rendered_component)
+        .to have_text(I18n.t("admin.reserved_identifiers.dialog.description_with_work_packages", count: 1))
+    end
+  end
+
+  context "with several affected work packages" do
+    before do
+      create(:work_package_semantic_alias, identifier: "old-id-1")
+      create(:work_package_semantic_alias, identifier: "old-id-2")
+    end
+
+    it "renders the pluralized description" do
+      expect(rendered_component)
+        .to have_text(I18n.t("admin.reserved_identifiers.dialog.description_with_work_packages", count: 2))
+    end
+  end
+end

spec/controllers/admin/settings/project_reserved_identifiers_controller_spec.rb

@@ -36,40 +36,33 @@ RSpec.describe Admin::Settings::ProjectReservedIdentifiersController do
   current_user { admin }
 
   describe "GET #index" do
-    context "in semantic mode", with_settings: { work_packages_identifier: "semantic" } do
-      it "redirects to the identifier settings page" do
-        get :index
-        expect(response).to redirect_to(admin_settings_work_packages_identifier_path)
-      end
-    end
+    shared_examples "lists reserved slugs of all formats" do
+      let!(:project) { create(:project) }
+
+      before do
+        FriendlyId::Slug.create!(sluggable: project, slug: "old-classic")
+        FriendlyId::Slug.create!(sluggable: project, slug: "OLDPROJ")
+        FriendlyId::Slug.create!(sluggable: project, slug: "12345")
+      end
 
-    context "in classic mode", with_settings: { work_packages_identifier: "classic" } do
       it "responds 200" do
         get :index
         expect(response).to have_http_status(:ok)
       end
 
-      context "with a classic reserved slug" do
-        let!(:project) { create(:project, identifier: "current-id") }
-
-        before { FriendlyId::Slug.create!(sluggable: project, slug: "old-classic") }
-
-        it "includes the slug in @slugs" do
-          get :index
-          expect(assigns(:slugs).map(&:slug)).to include("old-classic")
-        end
+      it "includes classic-format and semantic-format slugs, excluding pure-numeric ones" do
+        get :index
+        expect(assigns(:slugs).map(&:slug)).to include("old-classic", "OLDPROJ")
+        expect(assigns(:slugs).map(&:slug)).not_to include("12345")
       end
+    end
 
-      context "with a pure-numeric reserved slug" do
-        let!(:project) { create(:project, identifier: "current-id") }
+    context "in semantic mode", with_settings: { work_packages_identifier: "semantic" } do
+      it_behaves_like "lists reserved slugs of all formats"
+    end
 
-        before { FriendlyId::Slug.create!(sluggable: project, slug: "12345") }
-
-        it "excludes pure-numeric slugs" do
-          get :index
-          expect(assigns(:slugs).map(&:slug)).not_to include("12345")
-        end
-      end
+    context "in classic mode", with_settings: { work_packages_identifier: "classic" } do
+      it_behaves_like "lists reserved slugs of all formats"
     end
   end
 
@@ -154,26 +147,81 @@ RSpec.describe Admin::Settings::ProjectReservedIdentifiersController do
         expect(response.body).to include(I18n.t("admin.reserved_identifiers.identifier_not_found"))
       end
     end
+
+    describe "work package warning" do
+      render_views
+
+      let!(:project) { create(:project) }
+      let!(:slug) { FriendlyId::Slug.create!(sluggable: project, slug: "old-id") }
+
+      context "with affected work packages" do
+        before do
+          create(:work_package_semantic_alias, identifier: "old-id-1")
+          create(:work_package_semantic_alias, identifier: "old-id-2")
+        end
+
+        %w[semantic classic].each do |mode|
+          context "in #{mode} mode", with_settings: { work_packages_identifier: mode } do
+            it "shows the warning with the affected work package count" do
+              get :confirm_dialog, params: { id: slug.id }, format: :turbo_stream
+              expect(response.body)
+                .to include(I18n.t("admin.reserved_identifiers.dialog.description_with_work_packages", count: 2))
+            end
+          end
+        end
+      end
+
+      context "without affected work packages" do
+        it "does not show the warning" do
+          get :confirm_dialog, params: { id: slug.id }, format: :turbo_stream
+          expect(response.body).not_to include("work package")
+        end
+      end
+    end
   end
 
-  describe "DELETE #destroy", with_settings: { work_packages_identifier: "classic" } do
-    let!(:project) { create(:project, identifier: "current-id") }
+  describe "DELETE #destroy" do
+    let!(:project) { create(:project) }
     let!(:slug) { FriendlyId::Slug.create!(sluggable: project, slug: "old-id") }
 
-    it "destroys the slug and redirects with a flash notice" do
-      expect { delete :destroy, params: { id: slug.id } }
-        .to change(FriendlyId::Slug, :count).by(-1)
+    context "in classic mode", with_settings: { work_packages_identifier: "classic" } do
+      it "destroys the slug and redirects with a flash notice" do
+        expect { delete :destroy, params: { id: slug.id } }
+          .to change(FriendlyId::Slug, :count).by(-1)
 
-      expect(response).to redirect_to(admin_settings_project_reserved_identifiers_path)
-      expect(flash[:notice]).to include("old-id")
+        expect(response).to redirect_to(admin_settings_project_reserved_identifiers_path)
+        expect(flash[:notice]).to include("old-id")
+      end
+
+      it "also deletes work package aliases left over from a previous semantic phase" do
+        create(:work_package_semantic_alias, identifier: "old-id-1")
+
+        expect { delete :destroy, params: { id: slug.id } }
+          .to change(WorkPackageSemanticAlias, :count).by(-1)
+      end
+
+      context "with an unknown id" do
+        it "responds with a turbo stream error flash" do
+          delete :destroy, params: { id: 0 }, format: :turbo_stream
+          expect(response).to have_http_status(:not_found)
+          expect(response.media_type).to eq("text/vnd.turbo-stream.html")
+          expect(response.body).to include(I18n.t("admin.reserved_identifiers.identifier_not_found"))
+        end
+      end
     end
 
-    context "with an unknown id" do
-      it "responds with a turbo stream error flash" do
-        delete :destroy, params: { id: 0 }, format: :turbo_stream
-        expect(response).to have_http_status(:not_found)
-        expect(response.media_type).to eq("text/vnd.turbo-stream.html")
-        expect(response.body).to include(I18n.t("admin.reserved_identifiers.identifier_not_found"))
+    # Exact-prefix and case-sensitivity edge cases live in the service and
+    # scope specs; this guards the formerly mode-gated endpoint end to end.
+    context "in semantic mode", with_settings: { work_packages_identifier: "semantic" } do
+      it "destroys the slug and deletes its aliases" do
+        create(:work_package_semantic_alias, identifier: "old-id-1")
+
+        expect { delete :destroy, params: { id: slug.id } }
+          .to change(FriendlyId::Slug, :count).by(-1)
+          .and change(WorkPackageSemanticAlias, :count).by(-1)
+
+        expect(response).to redirect_to(admin_settings_project_reserved_identifiers_path)
+        expect(flash[:notice]).to include("old-id")
       end
     end
   end

spec/models/work_package/semantic_identifier_spec.rb

@@ -75,6 +75,39 @@ RSpec.describe WorkPackage::SemanticIdentifier do
     end
   end
 
+  describe ".for_slug_prefix" do
+    it "matches work packages whose identifier is of the form <slug>-<digits>" do
+      expect(WorkPackage.for_slug_prefix("MYPROJ")).to include(work_package)
+    end
+
+    it "does not over-match when another slug starts with the given slug plus a dash" do
+      work_package.update_columns(identifier: "my-project-42")
+      expect(WorkPackage.for_slug_prefix("my")).not_to include(work_package)
+    end
+
+    it "matches case-sensitively" do
+      expect(WorkPackage.for_slug_prefix("myproj")).not_to include(work_package)
+    end
+  end
+
+  describe ".resolving_via_slug_prefix" do
+    # The auto-registered work_package carries the prefix both in its
+    # identifier column and as an alias row.
+    it "returns work packages matched via column and alias exactly once" do
+      expect(WorkPackage.resolving_via_slug_prefix("MYPROJ")).to contain_exactly(work_package)
+    end
+
+    it "includes work packages matched only via an alias row" do
+      work_package.update_columns(identifier: nil, sequence_number: nil)
+      expect(WorkPackage.resolving_via_slug_prefix("MYPROJ")).to contain_exactly(work_package)
+    end
+
+    it "includes work packages matched only via the identifier column" do
+      work_package.semantic_aliases.delete_all
+      expect(WorkPackage.resolving_via_slug_prefix("MYPROJ")).to contain_exactly(work_package)
+    end
+  end
+
   describe "after_create registration", with_settings: { work_packages_identifier: "semantic" } do
     it "assigns a sequence number" do
       expect(work_package.reload.sequence_number).to eq(1)

spec/models/work_package_semantic_alias_spec.rb

@@ -66,6 +66,33 @@ RSpec.describe WorkPackageSemanticAlias do
     end
   end
 
+  describe ".for_slug_prefix" do
+    def alias_for(identifier)
+      described_class.create!(identifier:, work_package:)
+    end
+
+    it "matches identifiers of the exact form <slug>-<digits>" do
+      matching = alias_for("my-1")
+      alias_for("my-abc")
+
+      expect(described_class.for_slug_prefix("my")).to contain_exactly(matching)
+    end
+
+    it "does not over-match when another slug starts with the given slug plus a dash" do
+      matching = alias_for("my-2")
+      alias_for("my-project-42")
+
+      expect(described_class.for_slug_prefix("my")).to contain_exactly(matching)
+    end
+
+    it "matches case-sensitively" do
+      matching = alias_for("PROJ-1")
+      alias_for("proj-1")
+
+      expect(described_class.for_slug_prefix("PROJ")).to contain_exactly(matching)
+    end
+  end
+
   describe WorkPackage do
     describe "#semantic_aliases" do
       let(:wp) { create(:work_package) }

spec/services/project_identifiers/release_reserved_identifier_service_spec.rb

@@ -0,0 +1,105 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "spec_helper"
+
+RSpec.describe ProjectIdentifiers::ReleaseReservedIdentifierService do
+  let!(:project) { create(:project) }
+  let!(:slug) { FriendlyId::Slug.create!(sluggable: project, slug: "old-id") }
+
+  subject(:service_call) { described_class.new(slug).call }
+
+  shared_examples "releases the slug and its aliases" do
+    # All fixtures share one project graph — deliberately NOT the slug-owning
+    # project: creating work packages there would auto-seed "old-id-*" aliases
+    # in semantic mode and collide with the explicit ones below.
+    let(:alias_work_package) { create(:work_package) }
+    let!(:matching_aliases) do
+      [create(:work_package_semantic_alias, identifier: "old-id-1", work_package: alias_work_package),
+       create(:work_package_semantic_alias, identifier: "old-id-2", work_package: alias_work_package)]
+    end
+    let!(:other_prefix_alias) do
+      create(:work_package_semantic_alias, identifier: "old-id-extra-7", work_package: alias_work_package)
+    end
+    let!(:case_differing_alias) do
+      create(:work_package_semantic_alias, identifier: "OLD-ID-3", work_package: alias_work_package)
+    end
+    let!(:stale_wp) do
+      create(:work_package, project: alias_work_package.project)
+        .tap { |wp| wp.update_columns(identifier: "old-id-9", sequence_number: 9) }
+    end
+    let!(:decoy_wp) do
+      create(:work_package, project: alias_work_package.project)
+        .tap { |wp| wp.update_columns(identifier: "old-id-extra-9", sequence_number: 8) }
+    end
+
+    it "destroys the slug and returns a successful ServiceResult" do
+      expect(service_call).to be_success
+      expect(FriendlyId::Slug.exists?(slug.id)).to be(false)
+    end
+
+    it "clears stale identifiers only from work packages carrying the released prefix" do
+      service_call
+      expect(stale_wp.reload).to have_attributes(identifier: nil, sequence_number: nil)
+      expect(decoy_wp.reload).to have_attributes(identifier: "old-id-extra-9", sequence_number: 8)
+    end
+
+    it "deletes only the exact-prefix aliases" do
+      expect { service_call }.to change(WorkPackageSemanticAlias, :count).by(-2)
+
+      remaining = WorkPackageSemanticAlias.pluck(:identifier)
+      expect(remaining).to include("old-id-extra-7", "OLD-ID-3")
+      expect(remaining).not_to include("old-id-1", "old-id-2")
+    end
+
+    context "when destroying the slug fails" do
+      before do
+        allow(slug).to receive(:destroy!).and_raise(ActiveRecord::RecordNotDestroyed)
+      end
+
+      it "rolls back the alias deletion and the work package identifier clearing" do
+        expect { service_call }.to raise_error(ActiveRecord::RecordNotDestroyed)
+        expect(WorkPackageSemanticAlias.where(identifier: %w[old-id-1 old-id-2]).count).to eq(2)
+        expect(stale_wp.reload).to have_attributes(identifier: "old-id-9", sequence_number: 9)
+      end
+    end
+  end
+
+  context "in semantic mode", with_settings: { work_packages_identifier: "semantic" } do
+    it_behaves_like "releases the slug and its aliases"
+  end
+
+  # Aliases left over from a previous semantic phase are cleaned up in classic
+  # mode too — otherwise they would shadow the alias rows of a new project
+  # claiming the identifier after a later re-conversion.
+  context "in classic mode", with_settings: { work_packages_identifier: "classic" } do
+    it_behaves_like "releases the slug and its aliases"
+  end
+end