Fix parsing of connections where variables have the same name in different components

src/parser.cpp

@@ -1240,12 +1240,6 @@ void Parser::ParserImpl::loadConnection(const ModelPtr &model, const XmlNodePtr
             mapVariablesFound = true;
 
             if (!variable1Missing && !variable2Missing) {
-                if (variable1Name > variable2Name) {
-                    std::string tmp = variable1Name;
-                    variable1Name = variable2Name;
-                    variable2Name = tmp;
-                }
-
                 auto variableNamePair = std::make_pair(variable1Name, variable2Name);
 
                 NamePairList::const_iterator it = std::find_if(usedMapVariables.begin(), usedMapVariables.end(),

tests/connection/connection.cpp

@@ -1435,7 +1435,7 @@ TEST(Connection, repeatedMapVariables)
 
     const std::vector<std::string> expectedIssues = {
         "Connection in model 'connection' between 'variable1' and 'variable2' is not unique.",
-        "Connection in model 'connection' between 'variable3' and 'variable6' is not unique.",
+        "Connection in model 'connection' between 'variable6' and 'variable3' is not unique.",
     };
 
     EXPECT_EQ_ISSUES(expectedIssues, p);
@@ -1535,3 +1535,56 @@ TEST(Connection, addEquivalenceConnectionIdClearedAfterDisconnect)
     libcellml::Variable::addEquivalence(v1, v2);
     EXPECT_EQ("", libcellml::Variable::equivalenceConnectionId(v1, v2));
 }
+
+TEST(Connection, twoWayConnectionFromCellML1)
+{
+    auto p = libcellml::Parser::create(false);
+    auto m = p->parseModel(fileContents("cellml1X/connections.cellml"));
+
+    EXPECT_EQ(size_t(0), p->errorCount());
+}
+
+TEST(Connection, sameNamedVariablesInDifferentComponents)
+{
+    auto m = libcellml::Model::create("m");
+    auto c1 = libcellml::Component::create("c1");
+    auto c2 = libcellml::Component::create("c2");
+    auto v1c1 = libcellml::Variable::create("v1");
+    auto v2c1 = libcellml::Variable::create("v2");
+    auto v1c2 = libcellml::Variable::create("v1");
+    auto v2c2 = libcellml::Variable::create("v2");
+
+    m->addComponent(c1);
+    m->addComponent(c2);
+
+    c1->addVariable(v1c1);
+    c1->addVariable(v2c1);
+    c2->addVariable(v1c2);
+    c2->addVariable(v2c2);
+
+    v1c1->setUnits("dimensionless");
+    v1c1->setInterfaceType("public");
+    v2c1->setUnits("dimensionless");
+    v2c1->setInterfaceType("public");
+    v1c2->setUnits("dimensionless");
+    v1c2->setInterfaceType("public");
+    v2c2->setUnits("dimensionless");
+    v2c2->setInterfaceType("public");
+
+    libcellml::Variable::addEquivalence(v1c1, v2c2);
+    libcellml::Variable::addEquivalence(v2c1, v1c2);
+
+    auto v = libcellml::Validator::create();
+    v->validateModel(m);
+
+    EXPECT_EQ(size_t(0), v->issueCount());
+
+    auto printer = libcellml::Printer::create();
+
+    auto modelString = printer->printModel(m);
+
+    auto p = libcellml::Parser::create();
+    p->parseModel(modelString);
+
+    EXPECT_EQ(size_t(0), p->issueCount());
+}

tests/resources/cellml1X/connections.cellml

@@ -0,0 +1,55 @@
+<?xml version="1.0"?>
+<model xmlns="http://www.cellml.org/cellml/1.1#" xmlns:cmeta="http://www.cellml.org/metadata/1.0#" cmeta:id="MainDVad" name="MainDVad">
+
+  <units name="UnitP">
+    <unit multiplier="133" units="pascal"/>
+  </units>
+
+  <units name="UnitQ">
+    <unit units="UnitV"/>
+    <unit exponent="-1" units="second"/>
+  </units>
+
+  <component name="environment">
+    <variable cmeta:id="environment_t" name="t" public_interface="out" units="second"/>
+  </component>
+
+  <component name="Vessel">
+    <variable name="Pi" private_interface="in" public_interface="out" units="UnitP"/>
+    <variable name="Po" private_interface="out" public_interface="in" units="UnitP"/>
+    <variable name="Qi" private_interface="out" public_interface="in" units="UnitQ"/>
+    <variable name="Qm" private_interface="out" public_interface="in" units="UnitQ"/>
+    <variable name="Qo" private_interface="in" public_interface="out" units="UnitQ"/>
+    <variable name="t" private_interface="out" public_interface="in" units="second"/>
+    <variable name="Pm" private_interface="in" public_interface="out" units="UnitP"/>
+  </component>
+
+  <component name="LHeart">
+    <variable name="Pi" private_interface="in" public_interface="out" units="UnitP"/>
+    <variable name="Po" private_interface="out" public_interface="in" units="UnitP"/>
+    <variable name="Qi" private_interface="out" public_interface="in" units="UnitQ"/>
+    <variable name="Qm" private_interface="out" public_interface="in" units="UnitQ"/>
+    <variable name="Qo" private_interface="in" public_interface="out" units="UnitQ"/>
+    <variable name="t" private_interface="out" public_interface="in" units="second"/>
+    <variable name="Pm" private_interface="in" public_interface="out" units="UnitP"/>
+  </component>
+
+  <connection>
+    <map_components component_1="environment" component_2="LHeart"/>
+    <map_variables variable_1="t" variable_2="t"/>
+  </connection>
+
+  <connection>
+    <map_components component_1="environment" component_2="Vessel"/>
+    <map_variables variable_1="t" variable_2="t"/>
+  </connection>
+
+  <connection>
+    <map_components component_1="LHeart" component_2="Vessel"/>
+    <map_variables variable_1="Po" variable_2="Pi"/>
+    <map_variables variable_1="Qo" variable_2="Qi"/>
+    <map_variables variable_1="Pi" variable_2="Po"/>
+    <map_variables variable_1="Qi" variable_2="Qo"/>
+  </connection>
+
+</model>