* encoding.c (rb_find_encoding): new function find encoding from

  arbitrary object as a pointer to rb_encoding, and return NULL if
  not found.
* io.c (io_encoding_set): just warn unsupported encodings, but not
  exception.  [ruby-core:40726] [Bug #5567]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@34986 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 59 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index ee27a15ec5..5ae88b34f8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Mon Mar 12 19:23:13 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* encoding.c (rb_find_encoding): new function find encoding from
+	  arbitrary object as a pointer to rb_encoding, and return NULL if
+	  not found.
+
+	* io.c (io_encoding_set): just warn unsupported encodings, but not
+	  exception.  [ruby-core:40726] [Bug #5567]
+
 Mon Mar 12 19:03:32 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm_method.c (Init_eval_method): respond_to? and
diff --git a/encoding.c b/encoding.c
index dd20477906..1d82d4d3c4 100644
--- a/encoding.c
+++ b/encoding.c
@@ -161,7 +161,7 @@ rb_to_encoding_index(VALUE enc)
 
 /* Returns encoding index or UNSPECIFIED_ENCODING */
 static int
-str_to_encindex(VALUE enc)
+str_find_encindex(VALUE enc)
 {
     int idx;
 
@@ -170,6 +170,13 @@ str_to_encindex(VALUE enc)
 	rb_raise(rb_eArgError, "invalid name encoding (non ASCII)");
     }
     idx = rb_enc_find_index(StringValueCStr(enc));
+    return idx;
+}
+
+static int
+str_to_encindex(VALUE enc)
+{
+    int idx = str_find_encindex(enc);
     if (idx < 0) {
 	rb_raise(rb_eArgError, "unknown encoding name - %s", RSTRING_PTR(enc));
     }
@@ -189,6 +196,16 @@ rb_to_encoding(VALUE enc)
     return str_to_encoding(enc);
 }
 
+rb_encoding *
+rb_find_encoding(VALUE enc)
+{
+    int idx;
+    if (enc_check_encoding(enc) >= 0) return RDATA(enc)->data;
+    idx = str_find_encindex(enc);
+    if (idx < 0) return NULL;
+    return rb_enc_from_index(idx);
+}
+
 void
 rb_gc_mark_encodings(void)
 {
diff --git a/include/ruby/encoding.h b/include/ruby/encoding.h
index cced3d2688..ad2b614cd2 100644
--- a/include/ruby/encoding.h
+++ b/include/ruby/encoding.h
@@ -89,6 +89,7 @@ void rb_enc_set_index(VALUE obj, int encindex);
 int rb_enc_find_index(const char *name);
 int rb_to_encoding_index(VALUE);
 rb_encoding* rb_to_encoding(VALUE);
+rb_encoding* rb_find_encoding(VALUE);
 rb_encoding* rb_enc_get(VALUE);
 rb_encoding* rb_enc_compatible(VALUE,VALUE);
 rb_encoding* rb_enc_check(VALUE,VALUE);
diff --git a/io.c b/io.c
index d53633c937..169a5897a5 100644
--- a/io.c
+++ b/io.c
@@ -4604,6 +4604,12 @@ rb_io_ext_int_to_encs(rb_encoding *ext, rb_encoding *intern, rb_encoding **enc,
 }
 
 static void
+unsupported_encoding(const char *name)
+{
+    rb_warn("Unsupported encoding %s ignored", name);
+}
+
+static void
 parse_mode_enc(const char *estr, rb_encoding **enc_p, rb_encoding **enc2_p, int *fmode_p)
 {
     const char *p;
@@ -4647,7 +4653,7 @@ parse_mode_enc(const char *estr, rb_encoding **enc_p, rb_encoding **enc2_p, int
 	ext_enc = rb_enc_from_index(idx);
     else {
 	if (idx != -2)
-	    rb_warn("Unsupported encoding %s ignored", estr);
+	    unsupported_encoding(estr);
 	ext_enc = NULL;
     }
 
@@ -4660,7 +4666,7 @@ parse_mode_enc(const char *estr, rb_encoding **enc_p, rb_encoding **enc2_p, int
 	else {
 	    idx2 = rb_enc_find_index(p);
 	    if (idx2 < 0)
-		rb_warn("Unsupported encoding %s ignored", p);
+		unsupported_encoding(p);
 	    else if (idx2 == idx) {
 		rb_warn("Ignoring internal encoding %s: it is identical to external encoding %s", p, estr);
 		int_enc = (rb_encoding *)Qnil;
@@ -8709,6 +8715,14 @@ io_new_instance(VALUE args)
     return rb_class_new_instance(2, (VALUE*)args+1, *(VALUE*)args);
 }
 
+static rb_encoding *
+find_encoding(VALUE v)
+{
+    rb_encoding *enc = rb_find_encoding(v);
+    if (!enc) unsupported_encoding(StringValueCStr(v));
+    return enc;
+}
+
 static void
 io_encoding_set(rb_io_t *fptr, VALUE v1, VALUE v2, VALUE opt)
 {
@@ -8717,7 +8731,7 @@ io_encoding_set(rb_io_t *fptr, VALUE v1, VALUE v2, VALUE opt)
     VALUE ecopts, tmp;
 
     if (!NIL_P(v2)) {
-	enc2 = rb_to_encoding(v1);
+	enc2 = find_encoding(v1);
 	tmp = rb_check_string_type(v2);
 	if (!NIL_P(tmp)) {
 	    if (RSTRING_LEN(tmp) == 1 && RSTRING_PTR(tmp)[0] == '-') {
@@ -8726,14 +8740,14 @@ io_encoding_set(rb_io_t *fptr, VALUE v1, VALUE v2, VALUE opt)
 		enc2 = NULL;
 	    }
 	    else
-		enc = rb_to_encoding(v2);
+		enc = find_encoding(v2);
 	    if (enc == enc2) {
 		/* Special case - "-" => no transcoding */
 		enc2 = NULL;
 	    }
 	}
 	else
-	    enc = rb_to_encoding(v2);
+	    enc = find_encoding(v2);
 	SET_UNIVERSAL_NEWLINE_DECORATOR_IF_ENC2(enc2, ecflags);
 	ecflags = rb_econv_prepare_options(opt, &ecopts, ecflags);
     }
@@ -8752,7 +8766,7 @@ io_encoding_set(rb_io_t *fptr, VALUE v1, VALUE v2, VALUE opt)
                 ecflags = rb_econv_prepare_options(opt, &ecopts, ecflags);
 	    }
 	    else {
-		rb_io_ext_int_to_encs(rb_to_encoding(v1), NULL, &enc, &enc2);
+		rb_io_ext_int_to_encs(find_encoding(v1), NULL, &enc, &enc2);
 		SET_UNIVERSAL_NEWLINE_DECORATOR_IF_ENC2(enc2, ecflags);
                 ecopts = Qnil;
 	    }
diff --git a/test/ruby/test_io_m17n.rb b/test/ruby/test_io_m17n.rb
index d8916433ad..eccc27ac97 100644
--- a/test/ruby/test_io_m17n.rb
+++ b/test/ruby/test_io_m17n.rb
@@ -1060,6 +1060,17 @@ EOT
     }
   end
 
+  def test_set_encoding_unsupported
+    bug5567 = '[ruby-core:40726]'
+    IO.pipe do |r, w|
+      assert_nothing_raised(bug5567) do
+        assert_warn(/Unsupported/, bug5567) {r.set_encoding("fffffffffffxx")}
+        assert_warn(/Unsupported/, bug5567) {r.set_encoding("fffffffffffxx", "us-ascii")}
+        assert_warn(/Unsupported/, bug5567) {r.set_encoding("us-ascii", "fffffffffffxx")}
+      end
+    end
+  end
+
   def test_textmode_twice
     assert_raise(ArgumentError) {
       open(__FILE__, "rt", textmode: true) {|f|