streams: use Boolean return value for stdio_fseek.

* stream.c (stdio_seek): Handle new-style Boolean return from
stdio_fseek.

* sysif.c (stdio_fseek): Return an int indication that is 1
for success, 0 for failure. There was a mistaken assumption
here that fseeko returns the file offset, and the return value
in the fseek case was mistakenly harmonized, using a wasteful
call to stdio_ftell. The only call to this function relies
only on a Boolean success/fail indication.

* sysif.h (stdio_fseek): Declaration updated.

3 files changed, 5 insertions, 6 deletions

diff --git a/stream.c b/stream.c
index 7aae2d5a..53e76afb 100644
--- a/stream.c
+++ b/stream.c
@@ -675,7 +675,7 @@ static val stdio_seek(val stream, val offset, enum strm_whence whence)
     if (offset == zero && whence == strm_cur) {
       return stdio_ftell(h->f);
     } else {
-      if (stdio_fseek(h->f, offset, whence) != negone) {
+      if (stdio_fseek(h->f, offset, whence)) {
         utf8_decoder_init(&h->ud);
         h->unget_c = nil;
         return t;
diff --git a/sysif.c b/sysif.c
index ae469b07..04ed6ea5 100644
--- a/sysif.c
+++ b/sysif.c
@@ -1364,14 +1364,13 @@ val stdio_ftell(FILE *f)
 #endif
 }
 
-val stdio_fseek(FILE *f, val off, int whence)
+int stdio_fseek(FILE *f, val off, int whence)
 {
   val self = lit("seek-stream");
 #if HAVE_FSEEKO
-  return num_off_t(fseeko(f, off_t_num(off, self), whence));
+  return fseeko(f, off_t_num(off, self), whence) == 0;
 #else
-  int ret = fseek(f, c_long(off, self), whence);
-  return (ret == -1) ? num_fast(ret) : stdio_ftell(f);
+  return fseek(f, c_long(off, self), whence) == 0;
 #endif
 }
 
diff --git a/sysif.h b/sysif.h
index 02a5a1da..4e971e3d 100644
--- a/sysif.h
+++ b/sysif.h
@@ -59,7 +59,7 @@ val statf(val path);
 off_t off_t_num(val num, val self);
 val num_off_t(off_t offnum);
 val stdio_ftell(FILE *);
-val stdio_fseek(FILE *, val, int whence);
+int stdio_fseek(FILE *, val, int whence);
 #if HAVE_GETEUID
 void repress_privilege(void);
 void drop_privilege(void);