commit cd4dd9374d0fc65b070a61871801d306090f8375
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Mon Oct 01 22:12:02 2018 -0700
committer GitHub <noreply@github.com> Mon Oct 01 22:12:02 2018 -0700
tree 9034d7032562fa739ea857b15343758a730df793
parent 27d7f93f633f0163b96d0a95e312f0eb5615abfd

closes bpo-34868: Improve error message with '_' is combined with an invalid type specifier. (GH-9666)

(cherry picked from commit cbda8fc5d76b10bcbb92d927537576c229143836)

Co-authored-by: Benjamin Peterson <benjamin@python.org>

Python/formatter_unicode.c

diff --git a/Python/formatter_unicode.c b/Python/formatter_unicode.c
index 71e673d..ba09cc6 100644
--- a/Python/formatter_unicode.c
+++ b/Python/formatter_unicode.c
@@ -28,16 +28,17 @@
 }
 
 static void
-invalid_comma_type(Py_UCS4 presentation_type)
+invalid_thousands_separator_type(char specifier, Py_UCS4 presentation_type)
 {
+    assert(specifier == ',' || specifier == '_');
     if (presentation_type > 32 && presentation_type < 128)
         PyErr_Format(PyExc_ValueError,
-                     "Cannot specify ',' with '%c'.",
-                     (char)presentation_type);
+                     "Cannot specify '%c' with '%c'.",
+                     specifier, (char)presentation_type);
     else
         PyErr_Format(PyExc_ValueError,
-                     "Cannot specify ',' with '\\x%x'.",
-                     (unsigned int)presentation_type);
+                     "Cannot specify '%c' with '\\x%x'.",
+                     specifier, (unsigned int)presentation_type);
 }
 
 static void
@@ -117,8 +118,8 @@
 /* Locale type codes. LT_NO_LOCALE must be zero. */
 enum LocaleType {
     LT_NO_LOCALE = 0,
-    LT_DEFAULT_LOCALE,
-    LT_UNDERSCORE_LOCALE,
+    LT_DEFAULT_LOCALE = ',',
+    LT_UNDERSCORE_LOCALE = '_',
     LT_UNDER_FOUR_LOCALE,
     LT_CURRENT_LOCALE
 };
@@ -314,7 +315,7 @@
             }
             /* fall through */
         default:
-            invalid_comma_type(format->type);
+            invalid_thousands_separator_type(format->thousands_separators, format->type);
             return 0;
         }
     }