I: [PATCH] few asprintf error handling fixes

[Dmitry V. Levin]

On Wed, Jun 02, 2004 at 12:14:26PM -0700, Roland McGrath wrote:
[...]
> In that case any program that would be broken is working by pure luck and
> not just ambiguous definition.  I think it would be fine to change asprintf.

Ok, here is a patch.


-- 
ldv
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2004-06-03  Dmitry V. Levin <ldv@altlinux.org>

	* libio/vasprintf.c (_IO_vasprintf): Reset the result pointer
	to NULL on any error.
	* manual/stdio.texi: Reflect the change in asprintf API.

diff -uprk.orig glibc-2.3.3-200406020600.orig/libio/vasprintf.c glibc-2.3.3-200406020600/libio/vasprintf.c
--- glibc-2.3.3-200406020600.orig/libio/vasprintf.c	2003-06-03 13:41:51 +0400
+++ glibc-2.3.3-200406020600/libio/vasprintf.c	2004-06-03 01:50:21 +0400
@@ -48,7 +48,10 @@ _IO_vasprintf (result_ptr, format, args)
   _IO_size_t allocated;
   string = (char *) malloc (init_string_size);
   if (string == NULL)
-    return -1;
+    {
+      *result_ptr = NULL;
+      return -1;
+    }
 #ifdef _IO_MTSAFE_IO
   sf._sbf._f._lock = NULL;
 #endif
@@ -62,6 +65,7 @@ _IO_vasprintf (result_ptr, format, args)
   if (ret < 0)
     {
       free (sf._sbf._f._IO_buf_base);
+      *result_ptr = NULL;
       return ret;
     }
   /* Only use realloc if the size we need is of the same order of
diff -uprk.orig glibc-2.3.3-200406020600.orig/manual/stdio.texi glibc-2.3.3-200406020600/manual/stdio.texi
--- glibc-2.3.3-200406020600.orig/manual/stdio.texi	2002-07-03 16:41:42 +0400
+++ glibc-2.3.3-200406020600/manual/stdio.texi	2004-06-03 01:54:03 +0400
@@ -2397,7 +2397,9 @@ to the newly allocated string at that lo
 
 The return value is the number of characters allocated for the buffer, or
 less than zero if an error occurred. Usually this means that the buffer
-could not be allocated.
+could not be allocated, and the value of @var{ptr} in this situation is
+implementation-dependent (in glibc, @var{ptr} will be set to the null
+pointer, but this behavior should not be relied upon).
 
 Here is how to use @code{asprintf} to get the same result as the
 @code{snprintf} example, but more easily:
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