Create a "BEOS:APP_SIG" index by default

src/add-ons/kernel/file_systems/packagefs/Volume.cpp

@@ -30,6 +30,7 @@
 #include <package/hpkg/PackageEntryAttribute.h>
 #include <package/hpkg/PackageReaderImpl.h>
 
+#include "AttributeIndex.h"
 #include "DebugSupport.h"
 #include "kernel_interface.h"
 #include "LastModifiedIndex.h"
@@ -556,6 +557,21 @@ Volume::Mount(const char* parameterString)
 		fIndices.Insert(index);
 	}
 
+	// create a BEOS:APP_SIG index
+	{
+		AttributeIndex* index = new(std::nothrow) AttributeIndex;
+		if (index == NULL)
+			RETURN_ERROR(B_NO_MEMORY);
+
+		error = index->Init(this, "BEOS:APP_SIG", B_MIME_STRING_TYPE, 0);
+		if (error != B_OK) {
+			delete index;
+			RETURN_ERROR(error);
+		}
+
+		fIndices.Insert(index);
+	}
+
 	// get the mount parameters
 	const char* packages = NULL;
 	const char* volumeName = NULL;