Fix handling of basePlugin. Fixes #9562

Author: graemerocher

grails-core/src/main/groovy/org/grails/plugins/BinaryGrailsPlugin.java

@@ -19,7 +19,9 @@
 import grails.io.IOUtils;
 import grails.io.ResourceUtils;
 import grails.plugins.exceptions.PluginException;
+import grails.util.BuildSettings;
 import org.grails.core.io.StaticResourceLoader;
+import org.grails.io.support.GrailsResourceUtils;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.UrlResource;
 import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
@@ -78,6 +80,16 @@ public BinaryGrailsPlugin(Class<?> pluginClass, BinaryGrailsPluginDescriptor des
         }
         this.projectDirectory = isJar ? null : IOUtils.findApplicationDirectoryFile(pluginClass);
 
+        if(BuildSettings.BASE_DIR != null && projectDirectory != null) {
+            try {
+                if(projectDirectory.getCanonicalPath().startsWith(BuildSettings.BASE_DIR.getCanonicalPath())) {
+                    isBase = true;
+                }
+            } catch (IOException e) {
+                // ignore
+            }
+        }
+
         URL rootResourcesURL = IOUtils.findRootResourcesURL(pluginClass);
         if(rootResourcesURL == null) {
             throw new PluginException("Cannot evaluate plugin location for plugin " + pluginClass);