Have `scm_getc' honor the port's conversion strategy.

* libguile/ports.c (get_codepoint): Reset `pt->input_cd' upon failure.
  If `pt->ilseq_handler' is `SCM_ICONVEH_QUESTION_MARK', then return a
  question mark.
  [failure]: Use `scm_encoding_error' when raising an error.

* test-suite/lib.scm (exception:encoding-error): Adjust regexp.

* test-suite/tests/ports.test ("string ports")["read-char, wrong
  encoding, error", "read-char, wrong encoding, escape", "read-char,
  wrong encoding, substitute"]: New tests.

libguile/ports.c

@@ -1114,6 +1114,7 @@ utf8_to_codepoint (const scm_t_uint8 *utf8_buf, size_t size)
    failure.  */
 static scm_t_wchar
 get_codepoint (SCM port, char buf[SCM_MBCHAR_BUF_SIZE], size_t *len)
+#define FUNC_NAME "scm_getc"
 {
   int err, byte_read;
   size_t bytes_consumed, output_size;
@@ -1164,10 +1165,22 @@ get_codepoint (SCM port, char buf[SCM_MBCHAR_BUF_SIZE], size_t *len)
     }
 
   if (err != 0)
-    goto failure;
+    {
+      /* Reset the `iconv' state.  */
+      iconv (pt->input_cd, NULL, NULL, NULL, NULL);
+
+      if (pt->ilseq_handler == SCM_ICONVEH_QUESTION_MARK)
+	codepoint = '?';
+      else
+	/* Fail when the strategy is SCM_ICONVEH_ERROR or
+	   SCM_ICONVEH_ESCAPE_SEQUENCE (the latter doesn't make sense
+	   for input encoding errors.)  */
+	goto failure;
+    }
+  else
+    /* Convert the UTF8_BUF sequence to a Unicode code point.  */
+    codepoint = utf8_to_codepoint (utf8_buf, output_size);
 
-  /* Convert the UTF8_BUF sequence to a Unicode code point.  */
-  codepoint = utf8_to_codepoint (utf8_buf, output_size);
   update_port_lf (codepoint, port);
 
   *len = bytes_consumed;
@@ -1176,23 +1189,18 @@ get_codepoint (SCM port, char buf[SCM_MBCHAR_BUF_SIZE], size_t *len)
 
  failure:
   {
-    char *err_buf;
-    SCM err_str = scm_i_make_string (bytes_consumed, &err_buf);
-    memcpy (err_buf, buf, bytes_consumed);
+    SCM bv;
 
-    if (err == EILSEQ)
-      scm_misc_error (NULL, "input encoding error for ~s: ~s",
-		      scm_list_2 (scm_from_locale_string (scm_i_get_port_encoding (port)),
-				  err_str));
-    else
-      scm_misc_error (NULL, "input encoding error (invalid) for ~s: ~s\n", 
-		      scm_list_2 (scm_from_locale_string (scm_i_get_port_encoding (port)),
-				  err_str));
+    bv = scm_c_make_bytevector (bytes_consumed);
+    memcpy (SCM_BYTEVECTOR_CONTENTS (bv), buf, bytes_consumed);
+    scm_encoding_error (FUNC_NAME, err, "input decoding error",
+			pt->encoding, "UTF-8", bv);
   }
 
   /* Never gets here.  */
   return 0;
 }
+#undef FUNC_NAME
 
 /* Read a codepoint from PORT and return it.  */
 scm_t_wchar

test-suite/lib.scm

@@ -1,5 +1,6 @@
 ;;;; test-suite/lib.scm --- generic support for testing
-;;;; Copyright (C) 1999, 2000, 2001, 2004, 2006, 2007, 2009, 2010 Free Software Foundation, Inc.
+;;;; Copyright (C) 1999, 2000, 2001, 2004, 2006, 2007, 2009, 2010,
+;;;;   2011 Free Software Foundation, Inc.
 ;;;;
 ;;;; This program is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -279,7 +280,7 @@
 (define exception:system-error
   (cons 'system-error ".*"))
 (define exception:encoding-error
-  (cons 'encoding-error "(cannot convert to output locale|input locale conversion error)"))
+  (cons 'encoding-error "(cannot convert to output locale|input (locale conversion|decoding) error)"))
 (define exception:miscellaneous-error
   (cons 'misc-error "^.*"))
 (define exception:read-error

test-suite/tests/ports.test

@@ -23,7 +23,8 @@
   #:use-module (test-suite guile-test)
   #:use-module (ice-9 popen)
   #:use-module (ice-9 rdelim)
-  #:use-module (rnrs bytevectors))
+  #:use-module (rnrs bytevectors)
+  #:use-module ((rnrs io ports) #:select (open-bytevector-input-port)))
 
 (define (display-line . args)
   (for-each display args)
@@ -461,7 +462,31 @@
            (char=? (peek-char p) #\안)
            (char=? (peek-char p) #\안)
            (= (port-line p) 0)
-           (= (port-column p) 0)))))
+           (= (port-column p) 0))))
+
+  (pass-if-exception "read-char, wrong encoding, error"
+    exception:encoding-error
+    (let ((p (with-fluids ((%default-port-encoding "UTF-8"))
+               (open-bytevector-input-port #vu8(255 1 2 3)))))
+      (set-port-conversion-strategy! p 'error)
+      (read-char p)
+      #t))
+
+  (pass-if-exception "read-char, wrong encoding, escape"
+    exception:encoding-error
+    ;; `escape' should behave like `error'.
+    (let ((p (with-fluids ((%default-port-encoding "UTF-8"))
+               (open-bytevector-input-port #vu8(255 1 2 3)))))
+      (set-port-conversion-strategy! p 'escape)
+      (read-char p)
+      #t))
+
+  (pass-if "read-char, wrong encoding, substitute"
+    (let ((p (with-fluids ((%default-port-encoding "UTF-8"))
+               (open-bytevector-input-port #vu8(255 206 187 206 188)))))
+      (set-port-conversion-strategy! p 'substitute)
+      (equal? (list (read-char p) (read-char p) (read-char p))
+              '(#\? #\λ #\μ)))))
 
 (with-test-prefix "call-with-output-string"