From: Martin Panter <vadmium+py@gmail.com>
Date: 1481415516 0

Issue #25677: Correct syntax error caret for indented blocks.

Based on patch by Michael Layzell.

diff -r b396a2c97871 Lib/test/test_cmd_line_script.py
--- a/Lib/test/test_cmd_line_script.py	Sat Dec 10 14:15:22 2016 -0800
+++ b/Lib/test/test_cmd_line_script.py	Sun Dec 11 00:27:43 2016 +0000
@@ -10,6 +10,7 @@
 import os.path
 import py_compile
 import subprocess
+import io
 
 import textwrap
 from test import support
@@ -539,6 +540,38 @@
             text = stderr.decode('ascii')
             self.assertEqual(text, "some text")
 
+    def test_syntaxerror_unindented_caret_position(self):
+        script = "1 + 1 = 2\n"
+        with support.temp_dir() as script_dir:
+            script_name = _make_test_script(script_dir, 'script', script)
+            exitcode, stdout, stderr = assert_python_failure(script_name)
+            text = io.TextIOWrapper(io.BytesIO(stderr), 'ascii').read()
+            # Confirm that the caret is located under the first 1 character
+            self.assertIn("\n    1 + 1 = 2\n    ^", text)
+
+    def test_syntaxerror_indented_caret_position(self):
+        script = textwrap.dedent("""\
+            if True:
+                1 + 1 = 2
+            """)
+        with support.temp_dir() as script_dir:
+            script_name = _make_test_script(script_dir, 'script', script)
+            exitcode, stdout, stderr = assert_python_failure(script_name)
+            text = io.TextIOWrapper(io.BytesIO(stderr), 'ascii').read()
+            # Confirm that the caret is located under the first 1 character
+            self.assertIn("\n    1 + 1 = 2\n    ^", text)
+
+            # Try the same with a form feed at the start of the indented line
+            script = (
+                "if True:\n"
+                "\f    1 + 1 = 2\n"
+            )
+            script_name = _make_test_script(script_dir, "script", script)
+            exitcode, stdout, stderr = assert_python_failure(script_name)
+            text = io.TextIOWrapper(io.BytesIO(stderr), "ascii").read()
+            self.assertNotIn("\f", text)
+            self.assertIn("\n    1 + 1 = 2\n    ^", text)
+
 
 def test_main():
     support.run_unittest(CmdLineTest)
diff -r b396a2c97871 Misc/ACKS
--- a/Misc/ACKS	Sat Dec 10 14:15:22 2016 -0800
+++ b/Misc/ACKS	Sun Dec 11 00:27:43 2016 +0000
@@ -851,6 +851,7 @@
 Chris Lawrence
 Mark Lawrence
 Chris Laws
+Michael Layzell
 Michael Lazar
 Brian Leair
 Mathieu Leduc-Hamel
diff -r b396a2c97871 Misc/NEWS
--- a/Misc/NEWS	Sat Dec 10 14:15:22 2016 -0800
+++ b/Misc/NEWS	Sun Dec 11 00:27:43 2016 +0000
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #25677: Correct the positioning of the syntax error caret for
+  indented blocks.  Based on patch by Michael Layzell.
+
 - Issue #28918: Fix the cross compilation of xxlimited when Python has been
   built with Py_DEBUG defined.
 
diff -r b396a2c97871 Python/errors.c
--- a/Python/errors.c	Sat Dec 10 14:15:22 2016 -0800
+++ b/Python/errors.c	Sun Dec 11 00:27:43 2016 +0000
@@ -1142,11 +1142,8 @@
     }
     fclose(fp);
     if (i == lineno) {
-        char *p = linebuf;
         PyObject *res;
-        while (*p == ' ' || *p == '\t' || *p == '\014')
-            p++;
-        res = PyUnicode_FromString(p);
+        res = PyUnicode_FromString(linebuf);
         if (res == NULL)
             PyErr_Clear();
         return res;
diff -r b396a2c97871 Python/pythonrun.c
--- a/Python/pythonrun.c	Sat Dec 10 14:15:22 2016 -0800
+++ b/Python/pythonrun.c	Sun Dec 11 00:27:43 2016 +0000
@@ -528,7 +528,7 @@
             offset -= (int)(nl+1-text);
             text = nl+1;
         }
-        while (*text == ' ' || *text == '\t') {
+        while (*text == ' ' || *text == '\t' || *text == '\f') {
             text++;
             offset--;
         }