X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2F_PDCLIB%2Fprepwrite.c;h=0b31529d5d74693e40c97010d8d946acb549cbf8;hb=7015f5842d05bd5da32523048e4260e60e9e310c;hp=c5a4c127543b40b14f016c60b3ac0fd04272538d;hpb=9e1a90fce7fa732ebca11e98a41dc8418746b942;p=pdclib

diff --git a/functions/_PDCLIB/prepwrite.c b/functions/_PDCLIB/prepwrite.c
index c5a4c12..0b31529 100644
--- a/functions/_PDCLIB/prepwrite.c
+++ b/functions/_PDCLIB/prepwrite.c
@@ -7,6 +7,7 @@
 */
 
 #include <stdio.h>
+#include <errno.h>
 
 int _PDCLIB_prepwrite( struct _PDCLIB_file_t * stream )
 {
@@ -14,7 +15,11 @@ int _PDCLIB_prepwrite( struct _PDCLIB_file_t * stream )
          ( stream->status & ( _PDCLIB_FREAD | _PDCLIB_ERRORFLAG | _PDCLIB_WIDESTREAM | _PDCLIB_EOFFLAG ) ) ||
          ! ( stream->status & ( _PDCLIB_FWRITE | _PDCLIB_FAPPEND | _PDCLIB_FRW ) ) )
     {
-        _PDCLIB_errno = _PDCLIB_EIO;
+        /* Function called on illegal (e.g. input) stream.
+           See the comments on implementation-defined errno values in
+           <_PDCLIB_config.h>.
+        */
+        errno = EINVAL;
         stream->status |= _PDCLIB_ERRORFLAG;
         return EOF;
     }