bpo-32028: Fix custom print suggestion having leading whitespace in print statement

Lib/test/test_print.py

@@ -156,6 +156,15 @@ def test_string_with_excessive_whitespace(self):
 
         self.assertIn('print("Hello World", end=" ")', str(context.exception))
 
+    def test_string_with_leading_whitespace(self):
+        python2_print_str = '''if 1:
+            print "Hello World"
+        '''
+        with self.assertRaises(SyntaxError) as context:
+            exec(python2_print_str)
+
+        self.assertIn('print("Hello World")', str(context.exception))
+
     def test_stream_redirection_hint_for_py2_migration(self):
         # Test correct hint produced for Py2 redirection syntax
         with self.assertRaises(TypeError) as context:

Misc/NEWS.d/next/Core and Builtins/2017-12-03-22-29-13.bpo-32028.KC2w4Q.rst

@@ -0,0 +1,3 @@
+Leading whitespace is now correctly ignored when generating suggestions
+for converting Py2 print statements to Py3 builtin print function calls.
+Patch by Sanyam Khurana.

Objects/exceptions.c

@@ -2846,17 +2846,23 @@ _set_legacy_print_statement_msg(PySyntaxErrorObject *self, Py_ssize_t start)
 
     // PRINT_OFFSET is to remove `print ` word from the data.
     const int PRINT_OFFSET = 6;
-    Py_ssize_t text_len = PyUnicode_GET_LENGTH(self->text);
-    PyObject *data = PyUnicode_Substring(self->text, PRINT_OFFSET, text_len);
-
+    const int STRIP_BOTH = 2;
+    // Issue 32028: Handle case when whitespace is used with print call
+    PyObject *initial_data = _PyUnicode_XStrip(self->text, STRIP_BOTH, strip_sep_obj);
+    if (initial_data == NULL) {
+        Py_DECREF(strip_sep_obj);
+        return -1;
+    }
+    Py_ssize_t text_len = PyUnicode_GET_LENGTH(initial_data);
+    PyObject *data = PyUnicode_Substring(initial_data, PRINT_OFFSET, text_len);
+    Py_DECREF(initial_data);
     if (data == NULL) {
         Py_DECREF(strip_sep_obj);
         return -1;
     }
-    PyObject *new_data = _PyUnicode_XStrip(data, 2, strip_sep_obj);
+    PyObject *new_data = _PyUnicode_XStrip(data, STRIP_BOTH, strip_sep_obj);
     Py_DECREF(data);
     Py_DECREF(strip_sep_obj);
-
     if (new_data == NULL) {
         return -1;
     }