An XHTML document might have surrogate characters in it.
For example it might contain as text content idiograms like the ones defined here:
http://www.alanwood.net/unicode/cjk_unified_ideographs_extension_b.html
Such idiograms are each composed of two characters (high surrogate and low surrogate).
Right now the purifier (Purifier.purifyText(XMLString)) escapes the characters to "\u...." which is incorrect.
If the surrogate characters are correct, they should be written directly:
private final XMLStringBuffer fStringBuffer = new XMLStringBuffer();
/** Purify content. */
@Override
protected XMLString purifyText(XMLString text) {
fStringBuffer.length = 0;
for (int i = 0; i < text.length; i++) {
char c = text.ch[text.offset+i];
if (XMLChar.isInvalid(c)) {
boolean problem = true;
if(i < text.length - 1) {
int high = c;
int low = text.ch[text.offset + i + 1];
if (XMLChar.isHighSurrogate(high)) {
if (!XMLChar.isLowSurrogate(low)) {
//Invalid XML
} else {
int supplemental = XMLChar.supplemental((char) high, (char) low);
if (!XMLChar.isValid(supplemental)) {
//Invalid XML
} else {
//EXM-30072 Valid surrogate case, write the surrogate character directly.
problem = false;
fStringBuffer.append((char) high);
fStringBuffer.append((char) low);
i++;
}
}
} else {
//INvalid
}
}
if(problem) {
fStringBuffer.append("\\u"+toHexString(c,4));
}
}
else {
fStringBuffer.append(c);
}
}
return fStringBuffer;
}
Could you provide a unit test for this issue?
The TC would be something like: