Nicer output for negative error numbers in strerror_r

diff --git a/ChangeLog b/ChangeLog
index a1dca5d..fc2b7a8 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2011-05-21  Ulrich Drepper  <drepper@gmail.com>
 
+       * string/_strerror.c (__strerror_r): Print negative errors as signed
+       numbers.
+
        [BZ #12777]
        * iconvdata/cp1258.c (comp_table_data): Remove entry 0x00A5 0xEC.
        (decomp_table): Change U0385 entry to emit 0xA5 0xEC.

diff --git a/string/_strerror.c b/string/_strerror.c
index cb5d9e3..ad9b148 100644 (file)
--- a/string/_strerror.c
+++ b/string/_strerror.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991,93,95,96,97,98,2000,2002,2006
+/* Copyright (C) 1991,93,95,96,97,98,2000,2002,2006,2011
    Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -18,7 +18,9 @@
    02111-1307 USA.  */
 
 #include <libintl.h>
+#include <stdbool.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/param.h>
 #include <stdio-common/_itoa.h>
@@ -43,15 +45,21 @@ __strerror_r (int errnum, char *buf, size_t buflen)
         `int' of 8 bytes we never need more than 20 digits.  */
       char numbuf[21];
       const char *unk = _("Unknown error ");
-      const size_t unklen = strlen (unk);
+      size_t unklen = strlen (unk);
       char *p, *q;
+      bool negative = errnum < 0;
 
       numbuf[20] = '\0';
-      p = _itoa_word (errnum, &numbuf[20], 10, 0);
+      p = _itoa_word (abs (errnum), &numbuf[20], 10, 0);
 
       /* Now construct the result while taking care for the destination
         buffer size.  */
       q = __mempcpy (buf, unk, MIN (unklen, buflen));
+      if (negative && unklen < buflen)
+       {
+         *q++ = '-';
+         ++unklen;
+       }
       if (unklen < buflen)
        memcpy (q, p, MIN ((size_t) (&numbuf[21] - p), buflen - unklen));