[Input] Improve error message for Chemkin files with unrecognized sections

interfaces/cython/cantera/ck2cti.py

@@ -1908,6 +1908,9 @@ class Parser(object):
                         else:
                             transportLines.append(line)
                         line, comment = readline()
+                elif line.strip():
+                    raise InputParseError('Section starts with unrecognized keyword.'
+                        '\n"""\n{0}\n"""'.format(line.rstrip()))
 
                 if advance:
                     line, comment = readline()

interfaces/cython/cantera/test/test_convert.py

@@ -195,6 +195,13 @@ class chemkinConverterTest(utilities.CanteraTest):
         self.assertEqual(gas.n_species, 3)
         self.assertEqual(gas.n_reactions, 2)
 
+    def test_unrecognized_section(self):
+        with self.assertRaisesRegex(ck2cti.InputParseError, 'SPAM'):
+            convertMech(pjoin(self.test_data_dir, 'unrecognized-section.inp'),
+                        thermoFile=pjoin(self.test_data_dir, 'dummy-thermo.dat'),
+                        outName=pjoin(self.test_work_dir, 'unrecognized-section.cti'),
+                        quiet=True, permissive=True)
+
     def test_nasa9(self):
         convertMech(pjoin(self.test_data_dir, 'nasa9-test.inp'),
                     thermoFile=pjoin(self.test_data_dir, 'nasa9-test-therm.dat'),

test/data/unrecognized-section.inp

@@ -0,0 +1,14 @@
+Elements
+H  C
+
+SPECIES
+R1A R1B H P1
+END
+
+SPAM
+R1A + R1B = H + P1      1.2345e12  1.0  200.0
+END
+
+reactions cal/mol
+R1A + R1B = H + P1      1.2345e12  1.0  200.0
+R1A + R1A = H + P1      5.4321e10  1.0  500.0