TST: Add a test for gh-23533

2 files changed, 32 insertions, 0 deletions

diff --git a/numpy/f2py/tests/src/crackfortran/gh23533.f b/numpy/f2py/tests/src/crackfortran/gh23533.f
new file mode 100644
index 000000000..db522afa7
--- /dev/null
+++ b/numpy/f2py/tests/src/crackfortran/gh23533.f
@@ -0,0 +1,5 @@
+      SUBROUTINE EXAMPLE( )
+        IF( .TRUE. ) THEN
+            CALL DO_SOMETHING()
+        END IF ! ** .TRUE. **
+      END
diff --git a/numpy/f2py/tests/test_crackfortran.py b/numpy/f2py/tests/test_crackfortran.py
index dc0f7e27a..c20e2c2cf 100644
--- a/numpy/f2py/tests/test_crackfortran.py
+++ b/numpy/f2py/tests/test_crackfortran.py
@@ -135,6 +135,7 @@ class TestMarkinnerspaces:
         assert markinnerspaces("a 'b c' 'd e'") == "a 'b@_@c' 'd@_@e'"
         assert markinnerspaces(r'a "b c" "d e"') == r'a "b@_@c" "d@_@e"'
 
+
 class TestDimSpec(util.F2PyTest):
     """This test suite tests various expressions that are used as dimension
     specifications.
@@ -244,6 +245,7 @@ class TestModuleDeclaration:
         assert len(mod) == 1
         assert mod[0]["vars"]["abar"]["="] == "bar('abar')"
 
+
 class TestEval(util.F2PyTest):
     def test_eval_scalar(self):
         eval_scalar = crackfortran._eval_scalar
@@ -268,6 +270,7 @@ class TestFortranReader(util.F2PyTest):
         mod = crackfortran.crackfortran([str(f_path)])
         assert mod[0]['name'] == 'foo'
 
+
 class TestUnicodeComment(util.F2PyTest):
     sources = [util.getpath("tests", "src", "crackfortran", "unicode_comment.f90")]
 
@@ -278,6 +281,7 @@ class TestUnicodeComment(util.F2PyTest):
     def test_encoding_comment(self):
         self.module.foo(3)
 
+
 class TestNameArgsPatternBacktracking:
     @pytest.mark.parametrize(
         ['adversary'],
@@ -313,6 +317,19 @@ class TestNameArgsPatternBacktracking:
             # that should still be true.
             good_version_of_adversary = repeated_adversary + '@)@'
             assert nameargspattern.search(good_version_of_adversary)
+            if ii > start_reps:
+                # the hallmark of exponentially catastrophic backtracking
+                # is that runtime doubles for every added instance of
+                # the problematic pattern.
+                times_median_doubled += median > 2 * last_median
+                # also try to rule out non-exponential but still bad cases
+                # arbitrarily, we should set a hard limit of 10ms as too slow
+                assert median < trials_per_count * 0.01
+            last_median = median
+        # we accept that maybe the median might double once, due to
+        # the CPU scheduler acting weird or whatever. More than that
+        # seems suspicious.
+        assert times_median_doubled < 2
 
 
 class TestFunctionReturn(util.F2PyTest):
@@ -321,3 +338,13 @@ class TestFunctionReturn(util.F2PyTest):
     def test_function_rettype(self):
         # gh-23598
         assert self.module.intproduct(3, 4) == 12
+
+
+class TestFortranGroupCounters(util.F2PyTest):
+    def test_end_if_comment(self):
+        # gh-23533
+        fpath = util.getpath("tests", "src", "crackfortran", "gh23533.f")
+        try:
+            crackfortran.crackfortran([str(fpath)])
+        except Exception as exc:
+            assert False, f"'crackfortran.crackfortran' raised an exception {exc}"