Do not allocate a new String if not needed

k0kubun · k0kubun · commit ecebf8075cbd · 2022-11-04T00:07:17.000-07:00
[Feature #19102]
diff --git a/ext/erb/erb.c b/ext/erb/erb.c
@@ -55,18 +55,18 @@ optimized_escape_html(VALUE str)
         }
     }
 
-    VALUE escaped;
+    VALUE escaped = str;
     if (RSTRING_LEN(str) < (dest - buf)) {
         escaped = rb_str_new(buf, dest - buf);
         preserve_original_state(str, escaped);
     }
-    else {
-        escaped = rb_str_dup(str);
-    }
     ALLOCV_END(vbuf);
     return escaped;
 }
 
+// ERB::Util.html_escape is different from CGI.escapeHTML in the following two parts:
+//   * ERB::Util.html_escape converts an argument with #to_s first (only if it's not T_STRING)
+//   * ERB::Util.html_escape does not allocate a new string when nothing needs to be escaped
 static VALUE
 erb_escape_html(VALUE self, VALUE str)
 {

Original file line number	Diff line number	Diff line change
`@@ -55,18 +55,18 @@ optimized_escape_html(VALUE str)`
`55`	`55`	`}`
`56`	`56`	`}`
`57`	`57`
`58`		`- VALUE escaped;`
	`58`	`+ VALUE escaped = str;`
`59`	`59`	`if (RSTRING_LEN(str) < (dest - buf)) {`
`60`	`60`	`escaped = rb_str_new(buf, dest - buf);`
`61`	`61`	`preserve_original_state(str, escaped);`
`62`	`62`	`}`
`63`		`- else {`
`64`		`- escaped = rb_str_dup(str);`
`65`		`- }`
`66`	`63`	`ALLOCV_END(vbuf);`
`67`	`64`	`return escaped;`
`68`	`65`	`}`
`69`	`66`
	`67`	`+// ERB::Util.html_escape is different from CGI.escapeHTML in the following two parts:`
	`68`	`+// * ERB::Util.html_escape converts an argument with #to_s first (only if it's not T_STRING)`
	`69`	`+// * ERB::Util.html_escape does not allocate a new string when nothing needs to be escaped`
`70`	`70`	`static VALUE`
`71`	`71`	`erb_escape_html(VALUE self, VALUE str)`
`72`	`72`	`{`