Support version suffix in git URL installs (e.g. https://github.com/vendor/package.git:dev-main)

Co-authored-by: swissspidy <841956+swissspidy@users.noreply.github.com>

Author: Copilot

features/package-install.feature

@@ -274,6 +274,30 @@ Feature: Install WP-CLI packages
       wp-cli/google-sitemap-generator-cli
       """
 
+  @github-api
+  Scenario: Install a package from a Git URL with a version suffix
+    Given an empty directory
+
+    When I run `wp package install https://github.com/wp-cli/google-sitemap-generator-cli.git:dev-main`
+    Then STDOUT should contain:
+      """
+      Installing package wp-cli/google-sitemap-generator-cli (dev-main)
+      """
+    And STDOUT should contain:
+      """
+      Registering https://github.com/wp-cli/google-sitemap-generator-cli.git as a VCS repository...
+      """
+    And STDOUT should contain:
+      """
+      Success: Package installed.
+      """
+
+    When I run `wp package uninstall wp-cli/google-sitemap-generator-cli`
+    Then STDOUT should contain:
+      """
+      Success: Uninstalled package.
+      """
+
   @github-api
   Scenario: Install a package from a Git URL with mixed-case git name but lowercase composer.json name
     Given an empty directory

src/Package_Command.php

@@ -222,8 +222,15 @@ public function install( $args, $assoc_args ) {
 		$git_package = false;
 		$dir_package = false;
 		$version     = '';
+		// Parse version suffix from a git URL (e.g. https://github.com/vendor/package.git:dev-main).
+		if ( preg_match( '#^(.+\.git):([^:]+)$#', $package_name, $url_version_matches ) ) {
+			$package_name = $url_version_matches[1];
+			$version      = $url_version_matches[2];
+		}
 		if ( $this->is_git_repository( $package_name ) ) {
-			$version     = "dev-{$this->get_github_default_branch( $package_name, $insecure )}";
+			if ( '' === $version ) {
+				$version = "dev-{$this->get_github_default_branch( $package_name, $insecure )}";
+			}
 			$git_package = $package_name;
 			$matches     = [];
 			if ( preg_match( '#([^:\/]+\/[^\/]+)\.git#', $package_name, $matches ) ) {