Properly deal with multi-byte encodings by reusing existing code that does.

PR: 19187


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274509 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -106,6 +106,9 @@ Fixed bugs:
 * build.sh install had a problem on cygwin (with REALANTHOME). 
   Bugzilla Report 17257
 
+* <replaceregexp> didn't work for multi-byte encodings if byline was false.
+  Bugzilla Report 19187.
+
 Other changes:
 --------------
 * Six new Clearcase tasks added.

src/main/org/apache/tools/ant/taskdefs/optional/ReplaceRegExp.java

@@ -416,17 +416,7 @@ public class ReplaceRegExp extends Task {
 
                 pw.flush();
             } else {
-                int flen = (int) f.length();
-                char tmpBuf[] = new char[flen];
-                int numread = 0;
-                int totread = 0;
-
-                while (numread != -1 && totread < flen) {
-                    numread = br.read(tmpBuf, totread, flen);
-                    totread += numread;
-                }
-
-                String buf = new String(tmpBuf);
+                String buf = fileUtils.readFully(br);
 
                 String res = doReplace(regex, subs, buf, options);