The primary caller of nsStdEscape (in xpcom/io/nsEscape.cpp) is nsAppendURLEscapedString, which copies the result of nsStdEscape. That copying (including the construction and destruction of the nsAutoString) seems like about half a percent of the time on jrgm's tests in a profile I just did. If nsStdEscape had a second version, nsStdEscapeAppend, that didn't truncate (and nsStdEscape called nsStdEscapeAppend), then we could save this cost and get rid of nsAppendURLEscapedString. I'm giving this to darin because he's working on URL stuff and may even be doing something like this already. If not, give it back to me and I'll do it -- it's simple.

once my patch for bug 103916 lands, nsAppendURLEscapedString will no longer be needed. also, when the nsStandardURL lands, there won't be very much appending going on. we'll be saving the whole spec along with offsets and lengths to the individual URL parts. so, marking this bug as dependent on bug 103916.

this is now INVALID as of the recent standard url rewrite. nsAppendURLEscapedString is no longer executed.

VERIFIED: not used http://lxr.mozilla.org/mozilla/ident?i=nsAppendURLEscapedString