[PATCH] doc: isdigit and isxdigit are locale-independent

[Paul Eggert]

* doc/posix-functions/isdigit.texi:
* doc/posix-functions/isxdigit.texi:
Document that mingw and MSVC do not conform to the C standard,
which says that isdigit and isxdigit are independent of locale.
Issue pointed out by Florian Weimer in:
https://sourceware.org/pipermail/libc-alpha/2024-December/162362.html
---
 ChangeLog                         | 8 ++++++++
 doc/posix-functions/isdigit.texi  | 6 +++++-
 doc/posix-functions/isxdigit.texi | 6 +++++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 3a8e15beab..8b1b923d17 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2024-12-11  Paul Eggert  <eggert@cs.ucla.edu>
 
+       doc: isdigit and isxdigit are locale-independent
+       * doc/posix-functions/isdigit.texi:
+       * doc/posix-functions/isxdigit.texi:
+       Document that mingw and MSVC do not conform to the C standard,
+       which says that isdigit and isxdigit are independent of locale.
+       Issue pointed out by Florian Weimer in:
+       https://sourceware.org/pipermail/libc-alpha/2024-December/162362.html
+
        doc: document non-translation
        * doc/gnulib-tool.texi (Localization):
        Say what to do if you don’t want translations.
diff --git a/doc/posix-functions/isdigit.texi b/doc/posix-functions/isdigit.texi
index 7550d523e8..5077c66281 100644
--- a/doc/posix-functions/isdigit.texi
+++ b/doc/posix-functions/isdigit.texi
@@ -17,9 +17,13 @@ isdigit
 
 Portability problems not fixed by Gnulib:
 @itemize
+@item
+This function's behavior depends on locale, can return nonzero on
+arguments other than the usual decimal digits:
+mingw, MSVC.
 @end itemize
 
-Note: This function's behaviour depends on the locale, but does not support
+Note: This function does not support
 the multibyte characters that occur in strings in locales with
 @code{MB_CUR_MAX > 1} (this includes all the common UTF-8 locales).
 There are five alternative APIs:
diff --git a/doc/posix-functions/isxdigit.texi 
b/doc/posix-functions/isxdigit.texi
index 321af6e21f..a8c4e98c4f 100644
--- a/doc/posix-functions/isxdigit.texi
+++ b/doc/posix-functions/isxdigit.texi
@@ -17,9 +17,13 @@ isxdigit
 
 Portability problems not fixed by Gnulib:
 @itemize
+@item
+This function's behavior depends on locale, can return nonzero on
+arguments other than the usual hexadecimal digits:
+mingw, MSVC.
 @end itemize
 
-Note: This function's behaviour depends on the locale, but does not support
+Note: This function does not support
 the multibyte characters that occur in strings in locales with
 @code{MB_CUR_MAX > 1} (this includes all the common UTF-8 locales).
 There are five alternative APIs:
-- 
2.47.1