bpo-35560: Remove assertion from format(float, "n") (GH-11288)

Fix an assertion error in format() in debug build for floating point
formatting with "n" format, zero padding and small width. Release build is
not impacted. Patch by Karthikeyan Singaravelan.
(cherry picked from commit 3f7983a25a3d19779283c707fbdd5bc91b1587ef)

Co-authored-by: Xtreak <tir.karthi@gmail.com>

diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index 06ea90c207f56c98c0b0bd6c5389b0ca5f25c72f..49c1fbcd4ef8d377c0812088a1ab858929abfd0a 100644 (file)
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -701,6 +701,25 @@ class FormatTestCase(unittest.TestCase):
         self.assertEqual(format(1234.56, '.4'), '1.235e+03')
         self.assertEqual(format(12345.6, '.4'), '1.235e+04')
 
+    def test_issue35560(self):
+        self.assertEqual(format(123.0, '00'), '123.0')
+        self.assertEqual(format(123.34, '00f'), '123.340000')
+        self.assertEqual(format(123.34, '00e'), '1.233400e+02')
+        self.assertEqual(format(123.34, '00g'), '123.34')
+        self.assertEqual(format(123.34, '00.10f'), '123.3400000000')
+        self.assertEqual(format(123.34, '00.10e'), '1.2334000000e+02')
+        self.assertEqual(format(123.34, '00.10g'), '123.34')
+        self.assertEqual(format(123.34, '01f'), '123.340000')
+
+        self.assertEqual(format(-123.0, '00'), '-123.0')
+        self.assertEqual(format(-123.34, '00f'), '-123.340000')
+        self.assertEqual(format(-123.34, '00e'), '-1.233400e+02')
+        self.assertEqual(format(-123.34, '00g'), '-123.34')
+        self.assertEqual(format(-123.34, '00.10f'), '-123.3400000000')
+        self.assertEqual(format(-123.34, '00.10f'), '-123.3400000000')
+        self.assertEqual(format(-123.34, '00.10e'), '-1.2334000000e+02')
+        self.assertEqual(format(-123.34, '00.10g'), '-123.34')
+
 class ReprTestCase(unittest.TestCase):
     def test_repr(self):
         floats_file = open(os.path.join(os.path.split(__file__)[0],

diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-12-22-22-19-51.bpo-35560.9vMWSP.rst b/Misc/NEWS.d/next/Core and Builtins/2018-12-22-22-19-51.bpo-35560.9vMWSP.rst
new file mode 100644 (file)
index 0000000..01458f1
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-12-22-22-19-51.bpo-35560.9vMWSP.rst
@@ -0,0 +1,3 @@
+Fix an assertion error in :func:`format` in debug build for floating point
+formatting with "n" format, zero padding and small width. Release build is
+not impacted. Patch by Karthikeyan Singaravelan.

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index d46ab2a1e2ab8d24a0c39488d69729ba6165792c..35c8a24b7c0cd800c36bfd48254fb41dfaf66912 100644 (file)
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -9356,6 +9356,7 @@ _PyUnicode_InsertThousandsGrouping(
     PyObject *thousands_sep,
     Py_UCS4 *maxchar)
 {
+    min_width = Py_MAX(0, min_width);
     if (writer) {
         assert(digits != NULL);
         assert(maxchar == NULL);
@@ -9366,7 +9367,6 @@ _PyUnicode_InsertThousandsGrouping(
     }
     assert(0 <= d_pos);
     assert(0 <= n_digits);
-    assert(0 <= min_width);
     assert(grouping != NULL);
 
     if (digits != NULL) {