Warning: String-valued property starts with quote but doesn't end with quote

[Intelligent2013]

Source: #283

Warnings occur for asciimath text:

[mn2pdf] String-valued property starts with quote but doesn't end with quote: "C"_2"H"_2
[mn2pdf] String-valued property starts with quote but doesn't end with quote: "I"_2
[mn2pdf] String-valued property starts with quote but doesn't end with quote: "v"_1 + "v"_3
[mn2pdf] String-valued property starts with quote but doesn't end with quote: "v"_1 + "v"_3
[mn2pdf] String-valued property starts with quote but doesn't end with quote: "v"_1 + "v"_3 + "v"_4 + "v"_5

[Intelligent2013]

The message from java\org\apache\fop\fo\properties\StringProperty.java:

        /**
         * Make a new StringProperty object
         * @param propertyList not used
         * @param value String value of the new object
         * @param fo not used
         * @return the StringProperty object
         */
        public Property make(PropertyList propertyList, String value,
                             FObj fo) {
            // Work around the fact that most String properties are not
            // specified as actual String literals (with "" or '') since
            // the attribute values themselves are Strings!
            // If the value starts with ' or ", make sure it also ends with
            // this character
            // Otherwise, just take the whole value as the String
            int vlen = value.length() - 1;
            if (vlen > 0) {
                char q1 = value.charAt(0);
                if (q1 == '"' || q1 == '\'') {
                    if (value.charAt(vlen) == q1) {
                        return new StringProperty(value.substring(1, vlen));
                    }
                    log.warn("String-valued property starts with quote"
                                       + " but doesn't end with quote: "
                                       + value);
                    // fall through and use the entire value, including first quote
                }
                String str = checkValueKeywords(value);
                if (str != null) {
                    value = str;
                }
            }
            return StringProperty.getInstance(value);
        }

[Intelligent2013]

Fixed.