X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2F_PDCLIB%2Fprepwrite.c;h=0b31529d5d74693e40c97010d8d946acb549cbf8;hb=f2e874bbb30fa8857975a683a17dce7669524520;hp=774aeb21b29722917a3b18d2a41f9e75d75f7c5a;hpb=0d54a75af25ca44411e7c4190cc2a93a390e61a2;p=pdclib.old

diff --git a/functions/_PDCLIB/prepwrite.c b/functions/_PDCLIB/prepwrite.c
index 774aeb2..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;
     }
@@ -22,3 +27,14 @@ 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
+