find gem extension classes for uri-like filenames

depending on how the load-service resolves a require ($LOAD_PATH, argument
of require) it can happen that the ClassExtensionLibrary gets a uri-like
searchName. in such a case it needs to be treated as absolute file so the
class-name builder will try the right class-name as well.

fixes #2986

Sponsored By Lookout Inc.

Author: mkristian

core/src/main/java/org/jruby/runtime/load/ClassExtensionLibrary.java

@@ -28,9 +28,12 @@
 package org.jruby.runtime.load;
 
 import jnr.posix.JavaSecuredFile;
+
 import org.jruby.Ruby;
 
 import java.net.URL;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * The ClassExtensionLibrary wraps a class which implements BasicLibraryService,
@@ -44,6 +47,8 @@ public class ClassExtensionLibrary implements Library {
     private final Class theClass;
     private final String name;
 
+    private static Pattern URI_LIKE = Pattern.compile("(uri:classloader|file|jar|jar:file:uri):/?/?");
+
     /**
      * Try to locate an extension service in the current classloader resources. This happens
      * after the jar has been added to JRuby's URLClassLoader (JRubyClassLoader) and is how
@@ -63,11 +68,19 @@ public class ClassExtensionLibrary implements Library {
      * @return a ClassExtensionLibrary that will boot the ext, or null if none was found
      */
     static ClassExtensionLibrary tryFind(Ruby runtime, String searchName) {
+        final boolean isAbsolute;
+        Matcher matcher = URI_LIKE.matcher(searchName);
+        if (matcher.matches()) {
+            searchName = matcher.replaceFirst("");
+            isAbsolute = true;
+        }
+        else {
+            isAbsolute = new JavaSecuredFile(searchName).isAbsolute();
+        }
+
         // Create package name, by splitting on / and successively accumulating elements to form a class name
         String[] elts = searchName.split("/");
 
-        boolean isAbsolute = new JavaSecuredFile(searchName).isAbsolute();
-
         String simpleName = buildSimpleName(elts[elts.length - 1]);
 
         int firstElement = isAbsolute ? elts.length - 1 : 0;

test/test_load_gem_extensions.rb

@@ -0,0 +1,32 @@
+require 'test/unit'
+require 'test/test_helper'
+require 'rbconfig'
+require 'jruby/path_helper'
+
+class TestLoad < Test::Unit::TestCase
+  include TestHelper
+
+  def setup
+    @prev_loaded_features = $LOADED_FEATURES.dup
+    @prev_load_path = $LOAD_PATH.dup
+  end
+
+  def teardown
+    $LOADED_FEATURES.clear
+    $LOADED_FEATURES.concat(@prev_loaded_features)
+    $LOAD_PATH.clear
+    $LOAD_PATH.concat(@prev_load_path)
+  end
+
+  def test_require_extension_file_via_uri_protocol
+    require 'uri:file:./lib/ruby/shared/json/ext/parser'
+    # just check if extension class exists
+    JSON::Ext::Parser
+  end
+
+  def test_require_extension_file_via_uri_classloader_protocol
+    require 'uri:classloader:/lib/ruby/shared/json/ext/generator'
+    # just check if extension class exists
+    JSON::Ext::Generator
+  end
+end