Refactor to rw_random / rw_active port flags

* libguile/fports.c (fport_flush, fport_end_input): Move rw_active
  handling to ports.c.
* libguile/ioext.c (scm_redirect_port): Use scm_flush_unlocked instead
  of calling the flush function directly.
* libguile/ports.c (scm_c_make_port_with_encoding): Ports default to
  "rw_random" mode when they have a seek function.
  (scm_c_read_unlocked, scm_i_unget_bytes_unlocked)
  (scm_slow_get_byte_or_eof_unlocked)
  (scm_slow_peek_byte_or_eof_unlocked): Flush write buffer and set
  rw_active always in the same way, and only if rw_random is true.
  (scm_end_input_unlocked, scm_flush_unlocked): Clear rw_active here
  unconditionally.
  (scm_c_write_unlocked): Flush read buffer and set rw_active always in
  the same way, but only if rw_random is true.
  (scm_c_write, scm_lfwrite): Whitespace fixes.
  (scm_lfwrite_substr): Don't flush read buffer; lower-level code will
  do this.
  (scm_truncate_file): Use scm_flush_unlocked instead of calling the
  flush function directly.
* libguile/r6rs-ports.c (transcoded_port_flush): Don't muck with
  rw_active.
* libguile/read.c (scm_i_scan_for_encoding): Flush write buffer if
  needed in same way as ports.c.
* libguile/strports.c (st_end_input): Don't muck with rw_active.
  (scm_mkstrport): rw_random defaults to 1 now.

1 files changed, 5 insertions, 4 deletions

diff --git a/libguile/read.c b/libguile/read.c
index ecf27ff6e..346bcc969 100644
--- a/libguile/read.c
+++ b/libguile/read.c
@@ -2065,11 +2065,12 @@ scm_i_scan_for_encoding (SCM port)
 
   pt = SCM_PTAB_ENTRY (port);
 
-  if (pt->rw_active == SCM_PORT_WRITE)
-    scm_flush_unlocked (port);
-
   if (pt->rw_random)
-    pt->rw_active = SCM_PORT_READ;
+    {
+      if (pt->rw_active == SCM_PORT_WRITE)
+        scm_flush_unlocked (port);
+      pt->rw_active = SCM_PORT_READ;
+    }
 
   if (pt->read_pos == pt->read_end)
     {