tests/cgienv

hgweb: code selection without line numbers in file source view

All the source lines are put in a <pre> tag, which gives correct display and
copy&paste in both Chromium (WebKit) and FireFox: line numbers are not copied,
all the tabs and spaces are kept. This doesn't change the visual appearance
of the view compared to current hgweb version and doesn't use any JS code.
Also, stripes in this view are now generated clientside with CSS.

This implementation is chosen because other variants have important issues:

Strategy             FF              Chrome

current             D,LT,E,T,L        D,L
pre                 S,NW              S,NW
pre/div/nbsp        LT,E,T,TS,NW      TS,NW
pre/div/br          LT,E,T,NW         NW
ol/li/nbsp          LT,E,T,TS,AJ      TS,AJ
ol/li/br            LT,E,T,AJ         AJ
pre/span            LV                LV

Legend

Strategies:
- current: implemented in hgweb before this patch, i.e. divs for each line,
and line numbers links in the div too
- pre: the whole code in one pre tag with newlines, all line numbers
in another one with 'float: left'
- pre/div/{nbsp,br}: same as just 'pre', but separate divs for each line and
&nbsp; or <br> instead of empty lines (otherwise they are not copied at all)
- ol/li/{nbsp,br}: a single ol with li's and divs for each line,
&nbsp; or <br> same as in previous strategy
- pre/span: this patch

Problems:
D = (very minor) display problems, like wrong width of leading tabs
LT = loses leading/trailing whitespace
E = loses embedded whitespace
B = loses blank lines
T = loses tabs
L = selects line numbers
LV = (only) visually selects line numbers
LVE = (only) visually selects line numbers at empty lines
S = no stripes (and no ability to easily highlight
lines-which-are-linked-at in the future)
TS = space copied instead of empty line
AJ = get anchor links only with JS (they work even without)
NW = no linewrap easily possible (in future)

As for browser versions compatibility, the CSS tricks used are supported in
(according to caniuse.com):
a) line numbers generation with 'content:' property and CSS counters:
IE 8+, all other popular browsers (in pre-WebKit Opera numbers are being copied)
b) stripes ('nth-child' selector):
IE 8+, FF 3.5+, Safari 3.2+, Opera 9.5+, all other popular browsers
c) line numbers are not visually selected ('user-select:' property):
IE 10+, Opera 15.0+, all other popular browsers

This patch is based on a demo implementation by
Martin Geisler <[e-mail]>.

DOCUMENT_ROOT="/var/www/hg"; export DOCUMENT_ROOT
GATEWAY_INTERFACE="CGI/1.1"; export GATEWAY_INTERFACE
HTTP_ACCEPT="text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"; export HTTP_ACCEPT
HTTP_ACCEPT_CHARSET="ISO-8859-1,utf-8;q=0.7,*;q=0.7"; export HTTP_ACCEPT_CHARSET
HTTP_ACCEPT_ENCODING="gzip,deflate"; export HTTP_ACCEPT_ENCODING
HTTP_ACCEPT_LANGUAGE="en-us,en;q=0.5"; export HTTP_ACCEPT_LANGUAGE
HTTP_CACHE_CONTROL="max-age=0"; export HTTP_CACHE_CONTROL
HTTP_CONNECTION="keep-alive"; export HTTP_CONNECTION
HTTP_HOST="hg.omnifarious.org"; export HTTP_HOST
HTTP_KEEP_ALIVE="300"; export HTTP_KEEP_ALIVE
HTTP_USER_AGENT="Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.0.4) Gecko/20060608 Ubuntu/dapper-security Firefox/1.5.0.4"; export HTTP_USER_AGENT
PATH_INFO="/"; export PATH_INFO
PATH_TRANSLATED="/var/www/hg/index.html"; export PATH_TRANSLATED
QUERY_STRING=""; export QUERY_STRING
REMOTE_ADDR="127.0.0.2"; export REMOTE_ADDR
REMOTE_PORT="44703"; export REMOTE_PORT
REQUEST_METHOD="GET"; export REQUEST_METHOD
REQUEST_URI="/test/"; export REQUEST_URI
SCRIPT_FILENAME="/home/hopper/hg_public/test.cgi"; export SCRIPT_FILENAME
SCRIPT_NAME="/test"; export SCRIPT_NAME
SCRIPT_URI="http://hg.omnifarious.org/test/"; export SCRIPT_URI
SCRIPT_URL="/test/"; export SCRIPT_URL
SERVER_ADDR="127.0.0.1"; export SERVER_ADDR
SERVER_ADMIN="eric@localhost"; export SERVER_ADMIN
SERVER_NAME="hg.omnifarious.org"; export SERVER_NAME
SERVER_PORT="80"; export SERVER_PORT
SERVER_PROTOCOL="HTTP/1.1"; export SERVER_PROTOCOL
SERVER_SIGNATURE="<address>Apache/2.0.53 (Fedora) Server at hg.omnifarious.org Port 80</address>"; export SERVER_SIGNATURE
SERVER_SOFTWARE="Apache/2.0.53 (Fedora)"; export SERVER_SOFTWARE