Get rid of `LocalStore::addToStoreCommon`

I got it to just become `LocalStore::addToStoreFromDump`, cleanly taking
a store and then doing nothing too fancy with it.

`LocalStore::addToStore(...Path...)` is now just a simple wrapper with a
bare-bones sinkToSource of the right dump command.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc
index 141e9e976..4c72dc9f2 100644
--- a/src/libutil/serialise.cc
+++ b/src/libutil/serialise.cc
@@ -329,5 +329,18 @@ void StringSink::operator () (const unsigned char * data, size_t len)
     s->append((const char *) data, len);
 }
 
+size_t ChainSource::read(unsigned char * data, size_t len)
+{
+    if (useSecond) {
+        return source2.read(data, len);
+    } else {
+        try {
+            return source1.read(data, len);
+        } catch (EndOfFile &) {
+            useSecond = true;
+            return this->read(data, len);
+        }
+    }
+}
 
 }