[2380] make sure the new origin for $INCLUDE doesn't change post-include.

this seems to be the actual intent of the RFC, and it's compatible with
BIND 9, too.  This fix will resolve the remaining regression for the
old loadzone tests.

src/lib/dns/master_loader.cc

@@ -79,7 +79,7 @@ public:
         warn_rfc1035_ttl_(true)
     {}
 
-    void pushSource(const std::string& filename) {
+    void pushSource(const std::string& filename, const Name& current_origin) {
         std::string error;
         if (!lexer_.pushSource(filename.c_str(), &error)) {
             if (initialized_) {
@@ -91,7 +91,7 @@ public:
             }
         }
         // Store the current status, so we can recover it upon popSource
-        include_info_.push_back(IncludeInfo(active_origin_, last_name_));
+        include_info_.push_back(IncludeInfo(current_origin, last_name_));
         initialized_ = true;
         previous_name_ = false;
     }
@@ -182,9 +182,18 @@ private:
             filename(lexer_.getNextToken(MasterToken::QSTRING).getString());
 
         // There optionally can be an origin, that applies before the include.
+        // We need to save the currently active origin before calling
+        // doOrigin(), because it would update active_origin_ while we need
+        // to pass the active origin before recognizing the new origin to
+        // pushSource.  Note: RFC 1035 is not really clear on this: it reads
+        // "regardless of changes... within the included file", but the new
+        // origin is not really specified "within the included file".
+        // Nevertheless, this behavior is probably more likely to be the
+        // intent of the RFC, and it's compatible with BIND 9.
+        const Name current_origin = active_origin_;
         doOrigin(true);
 
-        pushSource(filename);
+        pushSource(filename, current_origin);
     }
 
     // A helper method for loadIncremental(). It parses part of an RR
@@ -512,7 +521,7 @@ MasterLoader::MasterLoaderImpl::loadIncremental(size_t count_limit) {
                   "Trying to load when already loaded");
     }
     if (!initialized_) {
-        pushSource(master_file_);
+        pushSource(master_file_, active_origin_);
     }
     size_t count = 0;
     while (ok_ && count < count_limit) {

src/lib/dns/tests/master_loader_unittest.cc

@@ -544,7 +544,7 @@ TEST_F(MasterLoaderTest, includeAndOrigin) {
         "@  1H  IN  A   192.0.2.1\n"
         // Then include the file with data and switch origin back
         "$INCLUDE " TEST_DATA_SRCDIR "/example.org example.org.\n"
-        // Another RR to see the switch survives after we exit include
+        // Another RR to see we fall back to the previous origin.
         "www    1H  IN  A   192.0.2.1\n";
     stringstream ss(include_string);
     setLoader(ss, Name("example.org"), RRClass::IN(),
@@ -557,7 +557,7 @@ TEST_F(MasterLoaderTest, includeAndOrigin) {
     // And check it's the correct data
     checkARR("www.example.org");
     checkBasicRRs();
-    checkARR("www.example.org");
+    checkARR("www.www.example.org");
 }
 
 // Like above, but the origin after include is bogus. The whole line should
@@ -582,7 +582,8 @@ TEST_F(MasterLoaderTest, includeAndBadOrigin) {
 
 // Check the origin doesn't get outside of the included file.
 TEST_F(MasterLoaderTest, includeOriginRestore) {
-    const string include_string = "$INCLUDE " TEST_DATA_SRCDIR "/origincheck.txt\n"
+    const string include_string =
+        "$INCLUDE " TEST_DATA_SRCDIR "/origincheck.txt\n"
         "@  1H  IN  A   192.0.2.1\n";
     stringstream ss(include_string);
     setLoader(ss, Name("example.org"), RRClass::IN(),