Fix 'package extract' with multiple explicit entries

* before adding a child to a parent entry, we need to check if the
  parent already contains that child, as otherwise duplicate children 
  with identical names would be added, which in turn messes up the
  handling of the entries that are to be extracted

src/bin/package/command_extract.cpp

@@ -185,6 +185,14 @@ struct Entry {
 	static status_t Create(Entry* parent, const char* name, bool implicit,
 		Entry*& _entry)
 	{
+		if (parent != NULL) {
+			Entry* entryInParent = parent->FindChild(name);
+			if (entryInParent != NULL) {
+				_entry = entryInParent;
+				return B_OK;
+			}
+		}
+
 		char* clonedName = strdup(name);
 		if (clonedName == NULL)
 			return B_NO_MEMORY;
@@ -804,7 +812,6 @@ do_extract(const char* packageFileName, const char* changeToDirectory,
 					entryName);
 				exit(1);
 			}
-
 			if (handler.AddFilterEntry(entryName) != B_OK)
 				exit(1);
 		}
@@ -836,6 +843,7 @@ do_extract(const char* packageFileName, const char* changeToDirectory,
 	// check whether all explicitly specified entries have been extracted
 	if (explicitEntryCount > 0) {
 		for (int i = 0; i < explicitEntryCount; i++) {
+			printf("check...en:%s\n", explicitEntries[i]);
 			if (Entry* entry = handler.FindFilterEntry(explicitEntries[i])) {
 				if (!entry->Seen()) {
 					fprintf(stderr, "Warning: Entry \"%s\" not found.\n",
@@ -893,7 +901,6 @@ command_extract(int argc, const char* const* argv)
 	const char* packageFileName = argv[optind++];
 	const char* const* explicitEntries = argv + optind;
 	int explicitEntryCount = argc - optind;
-
 	do_extract<VersionPolicyV2>(packageFileName, changeToDirectory,
 		packageInfoFileName, explicitEntries, explicitEntryCount, true);
 	do_extract<VersionPolicyV1>(packageFileName, changeToDirectory,