[PATCH] doc: document mbrtowc and mbrlen problem with empty input

[Paul Eggert]

* doc/posix-functions/mbrlen.texi (mbrlen):
* doc/posix-functions/mbrtowc.texi (mbrtowc):
Document portability problem when the input string is empty.  See:
https://sourceware.org/bugzilla/show_bug.cgi?id=16950
---
 ChangeLog                        | 6 ++++++
 doc/posix-functions/mbrlen.texi  | 8 ++++++++
 doc/posix-functions/mbrtowc.texi | 8 ++++++++
 3 files changed, 22 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 00126d5..2e59362 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2014-05-15  Paul Eggert  <address@hidden>
 
+       doc: document mbrtowc and mbrlen problem with empty input
+       * doc/posix-functions/mbrlen.texi (mbrlen):
+       * doc/posix-functions/mbrtowc.texi (mbrtowc):
+       Document portability problem when the input string is empty.  See:
+       https://sourceware.org/bugzilla/show_bug.cgi?id=16950
+
        doc: document exec* = spawn+exit bug with non-Cygwin Windows platforms
        Problem reported by Eli Zaretskii in:
        http://lists.gnu.org/archive/html/bug-grep/2014-05/msg00118.html
diff --git a/doc/posix-functions/mbrlen.texi b/doc/posix-functions/mbrlen.texi
index b2c9429..7db550e 100644
--- a/doc/posix-functions/mbrlen.texi
+++ b/doc/posix-functions/mbrlen.texi
@@ -12,6 +12,14 @@ Portability problems fixed by Gnulib:
 This function is missing on some platforms:
 Minix 3.1.8, HP-UX 11.00, IRIX 6.5, Solaris 2.6, mingw, Interix 3.5.
 @item
+This function returns 0 instead of @code{(size_t) -2} when the input
+is empty:
+glibc 2.19.
address@hidden
+This function returns @code{(size_t) -1} instead of @code{(size_t) -2}
+when the input is empty:
+AIX 5.1.
address@hidden
 This function does not put the state into non-initial state when parsing an
 incomplete multibyte character on some platforms:
 AIX 5.1, OSF/1 5.1.
diff --git a/doc/posix-functions/mbrtowc.texi b/doc/posix-functions/mbrtowc.texi
index 19b91f0..7c7f5fd 100644
--- a/doc/posix-functions/mbrtowc.texi
+++ b/doc/posix-functions/mbrtowc.texi
@@ -12,6 +12,14 @@ Portability problems fixed by Gnulib:
 This function is missing on some platforms:
 Minix 3.1.8, HP-UX 11.00, IRIX 6.5, Solaris 2.6, mingw, Interix 3.5.
 @item
+This function returns 0 instead of @code{(size_t) -2} when the input
+is empty:
+glibc 2.19.
address@hidden
+This function returns @code{(size_t) -1} instead of @code{(size_t) -2}
+when the input is empty:
+AIX 5.1.
address@hidden
 This function does not put the state into non-initial state when parsing an
 incomplete multibyte character on some platforms:
 AIX 5.1, OSF/1 5.1.
-- 
1.9.0