Addressed ticket #40 (non-standard errno values).

[pdclib] / functions / _PDCLIB / prepread.c

diff --git a/functions/_PDCLIB/prepread.c b/functions/_PDCLIB/prepread.c
index 53a2976dd403bd5fc11308f68a22a758473c062d..9111ff49b9eaf0a7309d932acd216aecc2e781a3 100644 (file)
--- a/functions/_PDCLIB/prepread.c
+++ b/functions/_PDCLIB/prepread.c
@@ -17,7 +17,11 @@ int _PDCLIB_prepread( struct _PDCLIB_file_t * stream )
          ( stream->status & ( _PDCLIB_FWRITE | _PDCLIB_FAPPEND | _PDCLIB_ERRORFLAG | _PDCLIB_WIDESTREAM | _PDCLIB_EOFFLAG ) ) ||
          ! ( stream->status & ( _PDCLIB_FREAD | _PDCLIB_FRW ) ) )
     {
-        _PDCLIB_errno = _PDCLIB_EIO;
+        /* Function called on illegal (e.g. output) stream.
+           See comments on implementation-defined errno values in
+           <_PDCLIB_config.h>.
+        */
+        _PDCLIB_errno = _PDCLIB_ERROR;
         stream->status |= _PDCLIB_ERRORFLAG;
         return EOF;
     }
@@ -32,3 +36,14 @@ int _PDCLIB_prepread( struct _PDCLIB_file_t * stream )
     }
 }
 
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    /* Testing covered by ftell.c */
+    return TEST_RESULTS;
+}
+
+#endif
+