Fixed a bug in ArchiveExtractor that caused it to fail on case-insens…

…itive file systems.

frontend-plugin-core/src/main/java/com/github/eirslett/maven/plugins/frontend/lib/ArchiveExtractor.java

@@ -107,12 +107,15 @@ public void extract(String archive, String destinationDirectory) throws ArchiveE
 				            while (tarEntry != null) {
 				                // Create a file for this tarEntry
 				                final File destPath = new File(destinationDirectory + File.separator + tarEntry.getName());
-		                    prepDestination(destPath, tarEntry.isDirectory());
-                                if (!destPath.getCanonicalPath().startsWith(destinationDirectory)) {
-                                     throw new IOException(
-                                             "Expanding " + tarEntry.getName() + " would create file outside of " + destinationDirectory
-                                     );
+		                        prepDestination(destPath, tarEntry.isDirectory());
+
+
+		                        if (!startsWithPath(destPath.getCanonicalPath(), destinationDirectory)) {
+                                    throw new IOException(
+                                            "Expanding " + tarEntry.getName() + " would create file outside of " + destinationDirectory
+                                    );
                                 }
+
 				                if (!tarEntry.isDirectory()) {
 				                    destPath.createNewFile();
 				                    boolean isExecutable = (tarEntry.getMode() & 0100) > 0;
@@ -138,4 +141,45 @@ public void extract(String archive, String destinationDirectory) throws ArchiveE
                     + "'", e);
         }
     }
+
+    /**
+     * Do multiple file system checks that should enable the plugin to work on any file system
+     * whether or not it's case sensitive or not.
+     * @param destPath
+     * @param destDir
+     * @return
+     */
+    private boolean startsWithPath(String destPath, String destDir) {
+        if (destDir.startsWith(destDir)) {
+            return true;
+        } else if (destDir.length() > destPath.length()) {
+            return false;
+        } else {
+            /*
+             * The first check should handle case-sensitive file systems. We need this
+             * in order to weed out case-sensitive file systems with a non-existent path
+             * that slipped through the first test.
+             */
+            if (new File(destPath).exists() && !(new File(destPath.toLowerCase()).exists())) {
+                return false;
+            }
+
+            boolean retVal = true;
+            for (int index = 0; index < destDir.length(); index++) {
+                char left = destPath.charAt(index);
+                char right = destDir.charAt(index);
+
+                if (left != right) {
+                    char leftUc = Character.toUpperCase(left);
+                    char rightUc = Character.toUpperCase(right);
+
+                    if (leftUc != rightUc) {
+                        retVal = false;
+                    }
+                }
+            }
+
+            return retVal;
+        }
+    }
 }