[1177] Don't propagate name exceptions from findPreviousName

They should be turned into DataSourceError instead, as they mean bad
data in the DB.

src/lib/datasrc/database.cc

@@ -614,8 +614,22 @@ DatabaseClient::Finder::find(const isc::dns::Name& name,
 
 Name
 DatabaseClient::Finder::findPreviousName(const Name& name) const {
-    return (Name(accessor_->findPreviousName(zone_id_,
-                                             name.reverse().toText())));
+    const string str(accessor_->findPreviousName(zone_id_,
+                                                 name.reverse().toText()));
+    try {
+        return (Name(str));
+    }
+    /*
+     * To avoid having the same code many times, we just catch all the
+     * exceptions and handle them in a common code below
+     */
+    catch (const isc::dns::EmptyLabel&) {}
+    catch (const isc::dns::TooLongLabel&) {}
+    catch (const isc::dns::BadLabelType&) {}
+    catch (const isc::dns::BadEscape&) {}
+    catch (const isc::dns::TooLongName&) {}
+    catch (const isc::dns::IncompleteName&) {}
+    isc_throw(DataSourceError, "Bad name " + str + " from findPreviousName");
 }
 
 Name

src/lib/datasrc/tests/database_unittest.cc

@@ -566,6 +566,8 @@ public:
                 return ("www.example.org.");
             } else if (rname == "org.example.badnsec2.") {
                 return ("badnsec1.example.org.");
+            } else if (rname == "org.example.brokenname.") {
+                return ("brokenname...example.org.");
             } else if (rname == "org.example.notimplnsec." ||
                        rname == "org.example.wild.here.") {
                 isc_throw(isc::NotImplemented, "Not implemented in this test");
@@ -2347,4 +2349,11 @@ TEST_F(MockDatabaseClientTest, missingNSEC) {
                  DataSourceError);
 }
 
+TEST_F(MockDatabaseClientTest, badName) {
+    shared_ptr<DatabaseClient::Finder> finder(this->getFinder());
+
+    EXPECT_THROW(finder->findPreviousName(Name("brokenname.example.org.")),
+                 DataSourceError);
+}
+
 }