X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstdio%2Fftell.c;h=74bb902407a4672dfcb3c4beacc8519b16ab11ab;hb=29387e76cd5cd340fe7d811dc9830931d3d0ec9b;hp=892c7b282b043f373da705166936886b81d52a13;hpb=6c8c4f80e32177f27f89b4aff3b7568a7afd4041;p=pdclib

diff --git a/functions/stdio/ftell.c b/functions/stdio/ftell.c
index 892c7b2..74bb902 100644
--- a/functions/stdio/ftell.c
+++ b/functions/stdio/ftell.c
@@ -7,26 +7,31 @@
 */
 
 #include <stdio.h>
+#include <stdint.h>
 #include <limits.h>
+#include <errno.h>
 
 #ifndef REGTEST
 
-long int ftell( struct _PDCLIB_file_t * stream )
+long int ftell_unlocked( struct _PDCLIB_file_t * stream )
 {
-    /* FIXME: A bit too fuzzy in the head now. stream->ungetidx should be in here
-             somewhere.
-    */
-    if ( stream->pos.offset > ( LONG_MAX - stream->bufidx ) )
+    uint_fast64_t off64 = _PDCLIB_ftell64_unlocked( stream );
+
+    if ( off64 > LONG_MAX )
     {
         /* integer overflow */
-        _PDCLIB_errno = _PDCLIB_EINVAL;
+        errno = ERANGE;
         return -1;
     }
-    /* Position of start-of-buffer, plus:
-       - buffered, unwritten content (for output streams), or
-       - already-parsed content from buffer (for input streams)
-    */
-    return (long int)( stream->pos.offset + stream->bufidx - stream->ungetidx );
+    return off64;
+}
+
+long int ftell( struct _PDCLIB_file_t * stream )
+{
+    flockfile( stream );
+    long int off = ftell_unlocked( stream );
+    funlockfile( stream );
+    return off;
 }
 
 #endif
@@ -50,6 +55,13 @@ int main( void )
     FILE * fh;
     TESTCASE( ( fh = tmpfile() ) != NULL );
     TESTCASE( setvbuf( fh, buffer, _IOLBF, 4 ) == 0 );
+    /* Testing ungetc() at offset 0 */
+    rewind( fh );
+    TESTCASE( ungetc( 'x', fh ) == 'x' );
+    TESTCASE( ftell( fh ) == -1l );
+    rewind( fh );
+    TESTCASE( ftell( fh ) == 0l );
+    /* Commence "normal" tests */
     TESTCASE( fputc( '1', fh ) == '1' );
     TESTCASE( fputc( '2', fh ) == '2' );
     TESTCASE( fputc( '3', fh ) == '3' );