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

[Victor Stinner]

https://github.com/python/cpython/commit/3f7983a25a3d19779283c707fbdd5bc91b1587ef
commit: 3f7983a25a3d19779283c707fbdd5bc91b1587ef
branch: master
author: Xtreak <tir.karthi at gmail.com>
committer: Victor Stinner <vstinner at redhat.com>
date: 2019-01-07T16:09:14+01:00
summary:

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.

files:
A Misc/NEWS.d/next/Core and Builtins/2018-12-22-22-19-51.bpo-35560.9vMWSP.rst
M Lib/test/test_float.py
M Objects/unicodeobject.c

diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index 06ea90c207f5..49c1fbcd4ef8 100644
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -701,6 +701,25 @@ def test_issue5864(self):
         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
index 000000000000..01458f11088e
--- /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 f1dcfe9ab72a..304ea7471f49 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -9381,6 +9381,7 @@ _PyUnicode_InsertThousandsGrouping(
     PyObject *thousands_sep,
     Py_UCS4 *maxchar)
 {
+    min_width = Py_MAX(0, min_width);
     if (writer) {
         assert(digits != NULL);
         assert(maxchar == NULL);
@@ -9391,7 +9392,6 @@ _PyUnicode_InsertThousandsGrouping(
     }
     assert(0 <= d_pos);
     assert(0 <= n_digits);
-    assert(0 <= min_width);
     assert(grouping != NULL);
 
     if (digits != NULL) {