Issue #9936: Fixed executable lines' search in the trace module.

Lib/test/test_trace.py

@@ -188,7 +188,6 @@ class TestLineCounts(unittest.TestCase):
             }
             self.assertEqual(tracer.results().counts, expected)
 
-
 class TestRunExecCounts(unittest.TestCase):
     """A simple sanity test of line-counting, via runctx (exec)"""
     def setUp(self):
@@ -285,8 +284,9 @@ class TestCoverage(unittest.TestCase):
         rmtree(TESTFN)
         unlink(TESTFN)
 
-    def _coverage(self, tracer):
-        tracer.run('from test import test_pprint; test_pprint.test_main()')
+    def _coverage(self, tracer,
+                  cmd='from test import test_pprint; test_pprint.test_main()'):
+        tracer.run(cmd)
         r = tracer.results()
         r.write_results(show_missing=True, summary=True, coverdir=TESTFN)
 
@@ -313,6 +313,25 @@ class TestCoverage(unittest.TestCase):
             files = os.listdir(TESTFN)
             self.assertEquals(files, [])
 
+    def test_issue9936(self):
+        tracer = trace.Trace(trace=0, count=1)
+        modname = 'test.tracedmodules.testmod'
+        # Ensure that the module is executed in import
+        if modname in sys.modules:
+            del sys.modules[modname]
+        cmd = ("import test.tracedmodules.testmod as t;"
+               "t.func(0); t.func2();")
+        with captured_stdout() as stdout:
+            self._coverage(tracer, cmd)
+        stdout.seek(0)
+        stdout.readline()
+        coverage = {}
+        for line in stdout:
+            lines, cov, module = line.split()[:3]
+            coverage[module] = (int(lines), int(cov[:-1]))
+        self.assertIn(modname, coverage)
+        self.assertEqual(coverage[modname], (5, 100))
+
 
 def test_main():
     run_unittest(__name__)

Lib/test/tracedmodules/testmod.py

 def func(x):
     b = x + 1
     return b + 2
+
+def func2():
+    """Test function for issue 9936 """
+    return (1,
+            2,
+            3)

Lib/trace.py

@@ -59,7 +59,7 @@ import token
 import tokenize
 import inspect
 import gc
-
+import dis
 import pickle
 
 def usage(outfile):
@@ -376,13 +376,7 @@ def find_lines_from_code(code, strs):
     """Return dict where keys are lines in the line number table."""
     linenos = {}
 
-    line_increments = code.co_lnotab[1::2]
-    table_length = len(line_increments)
-    docstring = False
-
-    lineno = code.co_firstlineno
-    for li in line_increments:
-        lineno += li
+    for _, lineno in dis.findlinestarts(code):
         if lineno not in strs:
             linenos[lineno] = 1
 

Misc/NEWS

@@ -68,6 +68,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #9936: Fixed executable lines' search in the trace module.
+
 - Issue #9790: Rework imports necessary for samefile and sameopenfile
   in ntpath.