Merge branch 'str-format-errors' of github.com:serhiy-storchaka/cpython into str-format-errors

Author: serhiy-storchaka

Lib/test/test_format.py

@@ -278,6 +278,8 @@ def test_common_format(self):
                         "unsupported format %z at position 4")
         test_exc_common("abc %Id", 1, ValueError,
                         "unsupported format %I at position 4")
+        test_exc_common("abc %'d", 1, ValueError,
+                        "stray % at position 4 or unexpected format character \"'\" at position 5")
         test_exc_common("abc %1 d", 1, ValueError,
                         "stray % at position 4 or unexpected format character ' ' at position 6")
         test_exc_common('abc % (x)r', {}, ValueError,
@@ -365,8 +367,6 @@ def test_str_format(self):
             print('Testing exceptions')
         test_exc('abc %b', 1, ValueError,
                  "unsupported format %b at position 4")
-        test_exc("abc %'d", 1, ValueError,
-                 "stray % at position 4 or unexpected format character ''' (U+0027) at position 5")
         test_exc("abc %\nd", 1, ValueError,
                  "stray % at position 4 or unexpected format character U+000A at position 5")
         test_exc("abc %\x1fd", 1, ValueError,

Objects/unicode_format.c

@@ -770,7 +770,14 @@ unicode_format_arg_format(struct unicode_formatter_t *ctx,
                          "unsupported format %%%c at position %zd",
                          (int)arg->ch, arg->fmtstart);
         }
-        else if (arg->ch >= 32 && arg->ch < 127 && arg->ch != '\'') {
+        else if (arg->ch == '\'') {
+            PyErr_Format(PyExc_ValueError,
+                         "stray %% at position %zd or unexpected "
+                         "format character \"'\" at position %zd",
+                         arg->fmtstart,
+                         ctx->fmtpos - 1);
+        }
+        else if (arg->ch >= 32 && arg->ch < 127) {
             PyErr_Format(PyExc_ValueError,
                          "stray %% at position %zd or unexpected "
                          "format character '%c' at position %zd",