This slightly modifies the HTML_TITLE_REGEX to fix two parsing errors.
The first occurred when title tags were empty (e.g. "<title></title>")
which was parsed as "</title". The second occurred when titles were a
single character (e.g. "<title>A</title>") which was not matched by the
regex, and so would fall back to link.base_url.
Now when tags are empty, it falls back to link.base_url, and single
character titles are parsed correctly.
The way the regex works now is still a bit wonky for some edge cases.
I couldn't find any cases of incorrect behavior, but it still might be
worth reworking more completely for robustness.
Incorrect hyphen placement in `URL_REGEX` was allowing it to match more
characters than intended. In a regex character class, a literal hyphen
can only appear as the first character in the class, or it will be
interpreted as the delimiter of a range of characters.
The issue fixed here caused the range of characters from `[$-_]`
be treated as valid URL characters, instead of the intended set of three
characters `[-_$]`. The incorrect range interpretation inadvertantly
included most ASCII punctuation, most importantly the angle brackets,
square brackets, and single quote that the expression uses
to mark the end of a match.
This causes the expression to match a URL that has a "hostname" portion
beginning with one of the intended "stop parsing" characters. For
example:
```
https://<b>www</b>.example.com/ # MATCHES but should not
https://[for example] # MATCHES but should not
scheme='https://' # MATCHES, including final quote, but should not
```
Some test cases have been added to the `URL_REGEX` assert in
archivebox.parsers to cover this possibility.
Previous method was splitting on the first whitespace, and missing the
version number when it appeared as `"Google Chrome 115.0.234.2342"`
instead of, i.e. `"Chromium 115.0.234.8283"`.
This commit changes the version detection to regex search for
whitespace, then one or more digits followed by a period, then at least
one more digit. Only the first sequence of digits is captured. Unless
Chrome radically changes their version numbering, this should capture
the first group of digits after the reported browser name, which would
be the major version.
the `bin_version` function means to modify the environment,
not replace it entirely. Fixes bugs that occur when it wipes out the
PATH environment variable, such as when running in a virtual
environment.
