1 files changed, 30 insertions, 0 deletions
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index cf0e2ad1b13b..771776f6a2c7 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -820,6 +820,28 @@ PathSet LocalStore::queryDerivationOutputs(const Path & path)
 }
 
 
+StringSet LocalStore::queryDerivationOutputNames(const Path & path)
+{
+    SQLiteTxn txn(db);
+    
+    SQLiteStmtUse use(stmtQueryDerivationOutputs);
+    stmtQueryDerivationOutputs.bind(queryValidPathId(path));
+    
+    StringSet outputNames;
+    int r;
+    while ((r = sqlite3_step(stmtQueryDerivationOutputs)) == SQLITE_ROW) {
+        const char * s = (const char *) sqlite3_column_text(stmtQueryDerivationOutputs, 0);
+        assert(s);
+        outputNames.insert(s);
+    }
+    
+    if (r != SQLITE_DONE)
+        throwSQLiteError(db, format("error getting output names of `%1%'") % path);
+
+    return outputNames;
+}
+
+
 void LocalStore::startSubstituter(const Path & substituter, RunningSubstituter & run)
 {
     if (run.pid != -1) return;
@@ -944,12 +966,14 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
     while (1) {
         try {
             SQLiteTxn txn(db);
+            PathSet paths;
     
             foreach (ValidPathInfos::const_iterator, i, infos) {
                 assert(i->hash.type == htSHA256);
                 /* !!! Maybe the registration info should be updated if the
                    path is already valid. */
                 if (!isValidPath(i->path)) addValidPath(*i);
+                paths.insert(i->path);
             }
 
             foreach (ValidPathInfos::const_iterator, i, infos) {
@@ -958,6 +982,12 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
                     addReference(referrer, queryValidPathId(*j));
             }
 
+            /* Do a topological sort of the paths.  This will throw an
+               error if a cycle is detected and roll back the
+               transaction.  Cycles can only occur when a derivation
+               has multiple outputs. */
+            topoSortPaths(*this, paths);
+
             txn.commit();
             break;
         } catch (SQLiteBusy & e) {