fix for GRAILS-2285 "ability to override a plugin's artefacts"

scripts/_GrailsClasspath.groovy

@@ -197,9 +197,11 @@ void setClasspath() {
         cpath << dir.file.absolutePath << File.pathSeparator
         // Adding the grails-app folders to the root loader causes re-load issues as
         // root loader returns old class before the grails GCL attempts to recompile it
-        //rootLoader?.addURL(dir.URL)
+        // rootLoader?.addURL(dir.URL)
     }
     cpath << classesDirPath << File.pathSeparator
+    cpath << pluginClassesDirPath << File.pathSeparator
+
     cpath << "${basedir}/web-app/WEB-INF" << File.pathSeparator
     for (jar in jarFiles) {
         cpath << jar.file.absolutePath << File.pathSeparator
@@ -212,9 +214,6 @@ void setClasspath() {
     compConfig.setClasspath(cpath.toString());
     compConfig.sourceEncoding = "UTF-8"
 
-//    rootLoader?.addURL(new File("${basedir}/grails-app/conf/hibernate").toURI().toURL())
-//    rootLoader?.addURL(new File("${basedir}/src/java").toURI().toURL())
-
     // The resources directory must be created before it is added to
     // the root loader, otherwise it is quietly ignored. In other words,
     // if the directory is created after its path has been added to the

scripts/_GrailsClean.groovy

@@ -45,6 +45,7 @@ target ( cleanCompiledSources: "Cleans compiled Java and Groovy sources" ) {
     ant.delete(dir:"${webInf}/lib")
     ant.delete(dir:"${basedir}/web-app/plugins")
     ant.delete(dir:classesDirPath)
+    ant.delete(dir:pluginClassesDirPath, failonerror:false)
     ant.delete(dir:resourcesDirPath)
     ant.delete(dir:testDirPath)
 }

scripts/_GrailsCompile.groovy

@@ -67,7 +67,7 @@ target(setCompilerSettings: "Updates the compile build settings based on args")
 target(compile : "Implementation of compilation phase") {
     depends(compilePlugins)
 
-    def classesDirPath = grailsSettings.classesDir.path
+    def classesDirPath = new File(grailsSettings.classesDir.path)
     ant.mkdir(dir:classesDirPath)
 
     profile("Compiling sources to location [$classesDirPath]") {
@@ -84,7 +84,9 @@ target(compile : "Implementation of compilation phase") {
             event("StatusFinal", ["Compilation error: ${e.message}"])
             exit(1)
         }
+
         classLoader.addURL(grailsSettings.classesDir.toURI().toURL())
+        classLoader.addURL(grailsSettings.pluginClassesDir.toURI().toURL())
 
         // If this is a plugin project, the descriptor is not included
         // in the compiler's source path. So, we manually compile it
@@ -97,7 +99,7 @@ target(compile : "Implementation of compilation phase") {
 target(compilePlugins: "Compiles source files of all referenced plugins.") {
     depends(setCompilerSettings, resolveDependencies)
 
-    def classesDirPath = grailsSettings.classesDir.path
+    def classesDirPath = pluginClassesDirPath
     ant.mkdir(dir:classesDirPath)
 
     profile("Compiling sources to location [$classesDirPath]") {
@@ -129,6 +131,8 @@ target(compilePlugins: "Compiles source files of all referenced plugins.") {
                 exclude(name: "**/resources.groovy")
                 javac(classpathref:classpathId, encoding:"UTF-8", debug:"yes")
             }
+
+
         }
     }
 }

scripts/_GrailsWar.groovy

@@ -120,15 +120,22 @@ target (war: "The implementation target") {
             fileset(dir:"${basedir}/grails-app", includes:"views/**")
             fileset(dir:"${resourcesDirPath}/grails-app", includes:"i18n/**")
         }
-        ant.copy(todir:"${stagingDir}/WEB-INF/classes") {
-            fileset(dir:classesDirPath) {
+
+        def classesDirExcludes = {
                 exclude(name:"hibernate")
                 exclude(name:"spring")
                 exclude(name:"hibernate/*")
                 exclude(name:"spring/*")
-            }
         }
-
+
+        ant.copy(todir:"${stagingDir}/WEB-INF/classes") {
+            fileset(dir:pluginClassesDirPath, classesDirExcludes) 
+        }
+
+        ant.copy(todir:"${stagingDir}/WEB-INF/classes", overwrite:true) {
+            fileset(dir:classesDirPath, classesDirExcludes) 
+        }
+
         ant.mkdir(dir:"${stagingDir}/WEB-INF/spring")
 
         ant.copy(todir:"${stagingDir}/WEB-INF/spring") {
@@ -357,9 +364,6 @@ protected def createDescriptorInternal(pluginInfos, resourceList) {
                         xml.resource(name)
                         addedResources.add name
                     }
-                    else {
-                        println "\tWARNING: Duplicate resource '${name}', using the last one in compile order."
-                    }
                 }
             }
             xml.plugins {