Fix broken interaction between readline and Unicode

This requires separate small fixes.

Readline has internal logic to deal with multi-byte characters, so
it wants bytes, not characters.

scm_c_read gets called by the vm when readline is activated, and it was
truncating multi-byte characters because soft ports didn't have the
UCS-4 capability.

Soft ports need the capability to read UCS-4 characters.  Since soft ports
may have a single byte buffer, full characters need to be stored into the
pushback buffer.

This broke the optimizations in scm_c_read for using an alternate buffer
for single-byte-buffered ports, because the opimization wasn't expecting
anything in the pushback buffer.

* libguile/vports.c (sf_fill_input): store complete chars, not single bytes

* libguile/ports.c (scm_c_read): don't use optimized path for non Latin-1.
  Add debug prints.

* libguile/string.h: make scm_i_from_stringn and scm_i_string_ref public
  so that readline can use them

* guile-readline/readline.c: read bytes, not complete chars, from the
  input port.  Convert output to the output port's locale

1 files changed, 9 insertions, 2 deletions

diff --git a/guile-readline/readline.c b/guile-readline/readline.c
index cbf4051cc..a665415bf 100644
--- a/guile-readline/readline.c
+++ b/guile-readline/readline.c
@@ -128,6 +128,7 @@ rl_free_line_state ()
 
 static int promptp;
 static SCM input_port;
+static SCM output_port;
 static SCM before_read;
 
 static int
@@ -138,7 +139,7 @@ current_input_getc (FILE *in SCM_UNUSED)
       scm_apply (before_read, SCM_EOL, SCM_EOL);
       promptp = 0;
     }
-  return scm_getc (input_port);
+  return scm_get_byte_or_eof (input_port);
 }
 
 static int in_readline = 0;
@@ -255,7 +256,12 @@ internal_readline (SCM text)
   promptp = 1;
   s = readline (prompt);
   if (s)
-    ret = scm_from_locale_string (s);
+    {
+      scm_t_port *pt = SCM_PTAB_ENTRY (output_port);
+      
+      ret = scm_i_from_stringn (s, strlen (s), pt->encoding, 
+                                SCM_FAILED_CONVERSION_ESCAPE_SEQUENCE);
+    }
   else 
     ret = SCM_EOF_VAL;
 
@@ -311,6 +317,7 @@ scm_readline_init_ports (SCM inp, SCM outp)
   }
 
   input_port = inp;
+  output_port = outp;
 #ifndef __MINGW32__
   rl_instream = stream_from_fport (inp, "r", s_scm_readline);
   rl_outstream = stream_from_fport (outp, "w", s_scm_readline);