X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2F_PDCLIB%2Fprepwrite.c;h=46f2d2f436d1b06067bcc7003e8bbd82b0dec1af;hb=b1fc26afebd4d557ff89a44bc21767a8704c3809;hp=774aeb21b29722917a3b18d2a41f9e75d75f7c5a;hpb=393020b6e48719d27699dea6b29e53025bbd5123;p=pdclib

diff --git a/functions/_PDCLIB/prepwrite.c b/functions/_PDCLIB/prepwrite.c
index 774aeb2..46f2d2f 100644
--- a/functions/_PDCLIB/prepwrite.c
+++ b/functions/_PDCLIB/prepwrite.c
@@ -1,5 +1,3 @@
-/* $Id$ */
-
 /* _PDCLIB_prepwrite( struct _PDCLIB_file_t * )
 
    This file is part of the Public Domain C Library (PDCLib).
@@ -14,7 +12,11 @@ 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>.
+        */
+        _PDCLIB_errno = _PDCLIB_ERROR;
         stream->status |= _PDCLIB_ERRORFLAG;
         return EOF;
     }
@@ -22,3 +24,14 @@ int _PDCLIB_prepwrite( struct _PDCLIB_file_t * stream )
     return 0;
 }
 
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    /* Testing covered by ftell.c */
+    return TEST_RESULTS;
+}
+
+#endif
+