Bugfix same variable twice on a line

ortoolslpparser/ortoolslpparser.py

@@ -73,6 +73,8 @@ def _parse_declaration(solver: pywraplp.Solver, core_line: str, line_nr: int, va
         if not re.match(_REGEXP_SINGLE_VAR_NAME, raw_var.strip()):
             raise ValueError("Non-permitted variable name (\"%s\") on line %d." % (raw_var, line_nr))
         clean_var = raw_var.strip()
+        if clean_var in var_names:
+            raise ValueError("Variable \"%s\" declared again on line %d." % (clean_var, line_nr))
         var_names.add(clean_var)
         solver.IntVar(-solver.infinity(), solver.infinity(), clean_var)
 
@@ -85,6 +87,9 @@ def _set_coefficients(solver: pywraplp.Solver, objective_or_constraint, coeffici
     if len(remainder) == 0:
         raise ValueError("No variables present in equation on line %d." % line_nr)
 
+    # All variables found
+    var_names_found = set()
+
     running_constant_sum = 0.0
     had_at_least_one_variable = False
     while len(remainder) != 0:
@@ -125,6 +130,9 @@ def _set_coefficients(solver: pywraplp.Solver, objective_or_constraint, coeffici
             # Retrieve clean variable name
             clean_var = var_name_match.group()
             var_names.add(clean_var)
+            if clean_var in var_names_found:
+                raise ValueError("Variable \"%s\" found more than once on line %d." % (clean_var, line_nr))
+            var_names_found.add(clean_var)
             solver_var = solver.LookupVariable(clean_var)
             if solver_var is None:
                 solver_var = solver.NumVar(-solver.infinity(), solver.infinity(), clean_var)
@@ -368,8 +376,7 @@ def parse_lp_file(lp_filename: str, use_solver=pywraplp.Solver.GLOP_LINEAR_PROGR
     Read in a linear program defined in a LP file.
 
     The LP specification format is similar to LPSolve 5.1.
-    For the accepted format, consult:
-    https://github.com/snkas/python-ortools-lp-parser
+    For the accepted format, consult the README of the python-ortools-lp-parser repository.
 
     :param lp_filename:  .lp file name (i.e. "/path/to/file.lp")
     :param use_solver:   Solver instance to use (optional)

tests/test_basic.py

@@ -989,3 +989,67 @@ class TestInvalid(unittest.TestCase):
         self.assertEqual(status, solver.OPTIMAL)
         self.assertEqual(solver.LookupVariable("x1").solution_value(), 30)
         self.assertEqual(solver.LookupVariable("x2").solution_value(), 50.1)
+
+    def test_twice_same_var_objective(self):
+
+        write_lp_program([
+            "max: x1 + x2 + x1;",
+            "x1 >= 0.0;",
+            "x1 <= 30.9;",
+            "24.4 >= x2 >= 29.8;",
+        ])
+
+        try:
+            ortoolslpparser.parse_lp_file(TEMP_FILE)
+            self.assertTrue(False)
+        except ValueError:
+            self.assertTrue(True)
+
+    def test_twice_same_var_constraint(self):
+
+        write_lp_program([
+            "max: x1 + x2;",
+            "x1 + 2x1 >= 0.0;",
+            "x1 <= 30.9;",
+            "24.4 >= x2 >= 29.8;",
+        ])
+
+        try:
+            ortoolslpparser.parse_lp_file(TEMP_FILE)
+            self.assertTrue(False)
+        except ValueError:
+            self.assertTrue(True)
+
+    def test_twice_declaration(self):
+
+        write_lp_program([
+            "max: x1 + x2;",
+            "x1 >= 0.0;",
+            "x1 <= 30.9;",
+            "24.4 >= x2 >= 29.8;",
+            "int x1;",
+            "int x1;"
+        ])
+
+        try:
+            ortoolslpparser.parse_lp_file(TEMP_FILE)
+            self.assertTrue(False)
+        except ValueError:
+            self.assertTrue(True)
+
+    def test_twice_declaration_same_line(self):
+
+        write_lp_program([
+            "max: x1 + x2;",
+            "x1 >= 0.0;",
+            "x1 <= 30.9;",
+            "24.4 >= x2 >= 29.8;",
+            "int x2;",
+            "int x1, x1;"
+        ])
+
+        try:
+            ortoolslpparser.parse_lp_file(TEMP_FILE)
+            self.assertTrue(False)
+        except ValueError:
+            self.assertTrue(True)