Single quotation marks within comments break source maps

Hi guys,

We ran into the problem of having to replace all our single quotation marks(') to 'multi' quotation marks(") in all our Less file comments, in order to get source maps running.

Versions:
OS ~ Ubuntu 14.04.1 LTS
Browser ~ Google Chrome 40.0.2214.111 (64-bit)
Node ~ node-v0.12.0-linux-x64
Lessc ~ v2.4.0 (https://github.com/less/less.js/commit/6fd2a5751cc8313481913bcb1623bf6c50089df8)

Command used:

bin/node less/bin/lessc foo.less foo.css --source-map-less-inline --source-map-map-inline

Broken CSS output example:

#titanic {
    float: none;
}
/* foo's bar */
/*# sourceMappingURL=data:application/json,%7B%22version%22%3A3%2C%22sources%22%3A%5Bfoo.less%22%5D%2C%22names%22%3A%5B%5D%2C%22mappings%22%3A%22AAAS%3BEACL%2CWAAA%22%2C%22sourcesContent%22%3A%5B%22%23titanic%20%7B%5Cn%20%20%20%20float%3A%20none%3B%5Cn%7D%5Cn%2F*%20foo's%20bar%20*%2F%22%5D%7D */

Working CSS output examples:

#titanic {
    float: none;
}
/* foos bar */
/*# sourceMappingURL=data:application/json,%7B%22version%22%3A3%2C%22sources%22%3A%5Bfoo.less%22%5D%2C%22names%22%3A%5B%5D%2C%22mappings%22%3A%22AAAS%3BEACL%2CWAAA%22%2C%22sourcesContent%22%3A%5B%22%23titanic%20%7B%5Cn%20%20%20%20float%3A%20none%3B%5Cn%7D%5Cn%2F*%20foos%20bar%20*%2F%22%5D%7D */

#titanic {
    float: none;
}
/* foo"s bar */
/*# sourceMappingURL=data:application/json,%7B%22version%22%3A3%2C%22sources%22%3A%5Bfoo.less%22%5D%2C%22names%22%3A%5B%5D%2C%22mappings%22%3A%22AAAS%3BEACL%2CWAAA%22%2C%22sourcesContent%22%3A%5B%22%23titanic%20%7B%5Cn%20%20%20%20float%3A%20none%3B%5Cn%7D%5Cn%2F*%20foo%5C%22s%20bar%20*%2F%22%5D%7D */

Reproduce the issue with the shown lessc command and a foo.less comment containing an apostrophe. Trace the inline source-map generation and add a regression test showing that the generated map remains valid while preserving the comment text; the existing broken and working CSS examples define the expected result.