Bug 610135

When a user enters a search, it will provide simple suggestions.  Since these
suggestions may contain whitespace, all of them are blindly wrapped with
double-quotes so that, upon auto-complete, the search translator will interpret
multiple words as a single search token.  The simple suggestions would look like:

"some whitespace"
"in my name"
"so i get double-quoted"
"by default"

However, this strategy is imperfect.  The issue lies in the fact that some results may actually have a double-quote in the suggestion itself.  If they do, then the suggestion will look like:

"suggestion with " in my name"

When the user selects this suggestion and executes the search, it will be parsed and interpreted as the following search tokens <suggestion with >, <in>, <my>, <name">

Although this search will work and may result somewhat close to the correct result, it could have also suggested something that would cause the expression parsing to fail:

"suggestion with"in my name"

Here the parser will interpret <suggestion with> as the first token and then bomb, because there is no whitespace between it and the next token in the expression.  As a result, the entire expression will be treated as invalid and no filters will be applied to the search.

This can be remedied by providing a more intelligent quoting mechanism.  The search suggestion generator can scan each suggestion and provide a quoting strategy that will work in a wider variety of cases:

1) do *not* wrap the suggestion in quotes, unless it contains whitespace (and thus requires wrapping to be interpreted as a single token)
2) if the expression does include whitespace then
2a) if the suggestion contains one or more double-quotes, but no single quotes, then wrap the suggestion in single-quotes
2b) conversely, if the suggestion contains one or more single-quotes but no double quotes, then wrap the suggestion in double-quotes

The only case this would fail to handle eloquently is if the suggestion has whitespace, contains single-quotes, and contains double-quotes.  If all three of those conditions are present, then the parser will either tokenize the expression incorrectly or the parse will fail altogether.  This, however, should be a rather rare circumstance.