Fix output of labels and references that contain characters with an UCS4

[features.git] / src / support / lstrings.C

diff --git a/src/support/lstrings.C b/src/support/lstrings.C
index 939d48531b78e621422d5a2a2ee8bc2fad22d9e9..9761da6d34ba6add3551cc7c2177020a49992b4e 100644 (file)
--- a/src/support/lstrings.C
+++ b/src/support/lstrings.C
@@ -702,21 +702,27 @@ string const rsplit(string const & a, string & piece, char delim)
 }
 
 
-// This function escapes 8-bit characters and other problematic
-// characters that cause problems in latex labels.
 docstring const escape(docstring const & lab)
 {
-       lyx::char_type hexdigit[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
-                             '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
+       char_type hexdigit[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
+                                  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
        docstring enc;
        for (docstring::size_type i = 0; i < lab.length(); ++i) {
-               lyx::char_type c = lab[i];
-               // FIXME We must change the following algorithm for UCS4
-               // chars, but that will be a file format change.
+               char_type c = lab[i];
                if (c >= 128 || c == '=' || c == '%') {
+                       // Although char_type is a 32 bit type we know that
+                       // UCS4 occupies only 21 bits, so we don't need to
+                       // encode bigger values. Test for 2^24 because we
+                       // can encode that with the 6 hex digits that are
+                       // needed for 21 bits anyway.
+                       BOOST_ASSERT(c < (1 << 24));
                        enc += '=';
-                       enc += hexdigit[c>>4];
-                       enc += hexdigit[c & 15];
+                       enc += hexdigit[(c>>20) & 15];
+                       enc += hexdigit[(c>>16) & 15];
+                       enc += hexdigit[(c>>12) & 15];
+                       enc += hexdigit[(c>> 8) & 15];
+                       enc += hexdigit[(c>> 4) & 15];
+                       enc += hexdigit[ c      & 15];
                } else {
                        enc += c;
                }