string.c: no terminator

* string.c (rb_str_{,l,r}strip_bang): rb_str_subseq() will not
  NUL-terminate the result string, in the future, so it will not
  be needed in other cases.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48280 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Nov  5 15:05:12 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (rb_str_{,l,r}strip_bang): rb_str_subseq() will not
+	  NUL-terminate the result string, in the future, so it will not
+	  be needed in other cases.
+
 Wed Nov  5 14:11:30 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* common.mk (lib/unicode_normalize/tables.rb): do nothing unless

NEWS

@@ -290,10 +290,10 @@ with all sufficient information, see the ChangeLog file.
 
 * rb_str_cat_cstr() added. This is same as `rb_str_cat2()`.
 
-* `rb_str_substr()` and `rb_str_subseq()` now share middle of a string,
-  but not only the end of a string.  Therefore, result strings may not
-  be NUL-terminated, `StringValueCStr()` is needed calling to obtain a
-  NUL-terminated C string.
+* `rb_str_substr()` and `rb_str_subseq()` will share middle of a string,
+  but not only the end of a string, in the futre.  Therefore, result
+  strings may not be NUL-terminated, `StringValueCStr()` is needed
+  calling to obtain a NUL-terminated C string.
 
 * rb_tracepoint_new() supports new internal events accessible only from C:
   * RUBY_INTERNAL_EVENT_GC_ENTER

string.c

@@ -128,7 +128,10 @@ VALUE rb_cSymbol;
 
 #define STR_ENC_GET(str) get_encoding(str)
 
-#if 1
+#if !defined SHARABLE_MIDDLE_SUBSTRING
+# define SHARABLE_MIDDLE_SUBSTRING 0
+#endif
+#if !SHARABLE_MIDDLE_SUBSTRING
 #define SHARABLE_SUBSTRING_P(beg, len, end) ((beg) + (len) == (end))
 #else
 #define SHARABLE_SUBSTRING_P(beg, len, end) 1
@@ -7227,7 +7230,9 @@ rb_str_lstrip_bang(VALUE str)
 	s = start + loffset;
 	memmove(start, s, len);
 	STR_SET_LEN(str, len);
+#if !SHARABLE_MIDDLE_SUBSTRING
 	TERM_FILL(start+len, rb_enc_mbminlen(enc));
+#endif
 	return str;
     }
     return Qnil;
@@ -7309,7 +7314,9 @@ rb_str_rstrip_bang(VALUE str)
 	long len = olen - roffset;
 
 	STR_SET_LEN(str, len);
+#if !SHARABLE_MIDDLE_SUBSTRING
 	TERM_FILL(start+len, rb_enc_mbminlen(enc));
+#endif
 	return str;
     }
     return Qnil;
@@ -7371,7 +7378,9 @@ rb_str_strip_bang(VALUE str)
 	    memmove(start, start + loffset, len);
 	}
 	STR_SET_LEN(str, len);
+#if !SHARABLE_MIDDLE_SUBSTRING
 	TERM_FILL(start+len, rb_enc_mbminlen(enc));
+#endif
 	return str;
     }
     return Qnil;