gitweb: visually highlight source lines when hovering over line numbers

gitweb: visually highlight source lines when hovering over line numbers

Due to how the line links now reside outside of the source lines, hovering over
line numbers doesn't count as hovering over the appropriate source line. It can
be worked around by using a "+" css selector. However, it's necessary to
reorder the elements and put <a> before <span> (which is actually quite
logical). It works without further css tweaks because <a> is already
absolute-positioned and so the order doesn't matter visually.

--- a/mercurial/templates/gitweb/map	Tue Oct 13 14:17:15 2015 -0700
+++ b/mercurial/templates/gitweb/map	Thu Oct 15 00:04:58 2015 +0800
@@ -93,7 +93,7 @@
 filecomparison = filecomparison.tmpl
 filelog = filelog.tmpl
 fileline = '
-  <span id="{lineid}">{strip(line|escape, '\r\n')}</span><a href="#{lineid}"></a>'
+  <a href="#{lineid}"></a><span id="{lineid}">{strip(line|escape, '\r\n')}</span>'
 annotateline = '
   <tr id="{lineid}" style="font-family:monospace" class="parity{parity}">
     <td class="linenr" style="text-align: right;">
@@ -104,13 +104,13 @@
     <td><pre>{line|escape}</pre></td>
   </tr>'
 difflineplus = '
-  <span id="{lineid}" class="difflineplus">{strip(line|escape, '\r\n')}</span><a href="#{lineid}"></a>'
+  <a href="#{lineid}"></a><span id="{lineid}" class="difflineplus">{strip(line|escape, '\r\n')}</span>'
 difflineminus = '
-  <span id="{lineid}" class="difflineminus">{strip(line|escape, '\r\n')}</span><a href="#{lineid}"></a>'
+  <a href="#{lineid}"></a><span id="{lineid}" class="difflineminus">{strip(line|escape, '\r\n')}</span>'
 difflineat = '
-  <span id="{lineid}" class="difflineat">{strip(line|escape, '\r\n')}</span><a href="#{lineid}"></a>'
+  <a href="#{lineid}"></a><span id="{lineid}" class="difflineat">{strip(line|escape, '\r\n')}</span>'
 diffline = '
-  <span id="{lineid}">{strip(line|escape, '\r\n')}</span><a href="#{lineid}"></a>'
+  <a href="#{lineid}"></a><span id="{lineid}">{strip(line|escape, '\r\n')}</span>'
 
 comparisonblock ='
   <tbody class="block">

--- a/mercurial/templates/static/style-gitweb.css	Tue Oct 13 14:17:15 2015 -0700
+++ b/mercurial/templates/static/style-gitweb.css	Thu Oct 15 00:04:58 2015 +0800
@@ -29,9 +29,12 @@
 a.list:hover { text-decoration:underline; color:#880000; }
 table { padding:8px 4px; }
 th { padding:2px 5px; font-size:12px; text-align:left; }
-tr.light:hover, .parity0:hover, pre.sourcelines.stripes > :nth-child(4n+1):hover { background-color:#edece6; }
-tr.dark, .parity1, pre.sourcelines.stripes > :nth-child(4n+3) { background-color:#f6f6f0; }
-tr.dark:hover, .parity1:hover, pre.sourcelines.stripes > :nth-child(4n+3):hover { background-color:#edece6; }
+tr.dark, .parity1, pre.sourcelines.stripes > :nth-child(4n+4) { background-color:#f6f6f0; }
+tr.light:hover, .parity0:hover, tr.dark:hover, .parity1:hover,
+pre.sourcelines.stripes > :nth-child(4n+2):hover,
+pre.sourcelines.stripes > :nth-child(4n+4):hover,
+pre.sourcelines.stripes > :nth-child(4n+1):hover + :nth-child(4n+2),
+pre.sourcelines.stripes > :nth-child(4n+3):hover + :nth-child(4n+4) { background-color:#edece6; }
 td { padding:2px 5px; font-size:12px; vertical-align:top; }
 td.closed { background-color: #99f; }
 td.link { padding:2px 5px; font-family:sans-serif; font-size:10px; }

--- a/tests/test-hgweb.t	Tue Oct 13 14:17:15 2015 -0700
+++ b/tests/test-hgweb.t	Thu Oct 15 00:04:58 2015 +0800
@@ -340,7 +340,7 @@
 
   $ get-with-headers.py --twice localhost:$HGPORT 'static/style-gitweb.css' - date etag server
   200 Script output follows
-  content-length: 6412
+  content-length: 6521
   content-type: text/css
   
   body { font-family: sans-serif; font-size: 12px; border:solid #d9d8d1; border-width:1px; margin:10px; background: white; color: black; }
@@ -374,9 +374,12 @@
   a.list:hover { text-decoration:underline; color:#880000; }
   table { padding:8px 4px; }
   th { padding:2px 5px; font-size:12px; text-align:left; }
-  tr.light:hover, .parity0:hover, pre.sourcelines.stripes > :nth-child(4n+1):hover { background-color:#edece6; }
-  tr.dark, .parity1, pre.sourcelines.stripes > :nth-child(4n+3) { background-color:#f6f6f0; }
-  tr.dark:hover, .parity1:hover, pre.sourcelines.stripes > :nth-child(4n+3):hover { background-color:#edece6; }
+  tr.dark, .parity1, pre.sourcelines.stripes > :nth-child(4n+4) { background-color:#f6f6f0; }
+  tr.light:hover, .parity0:hover, tr.dark:hover, .parity1:hover,
+  pre.sourcelines.stripes > :nth-child(4n+2):hover,
+  pre.sourcelines.stripes > :nth-child(4n+4):hover,
+  pre.sourcelines.stripes > :nth-child(4n+1):hover + :nth-child(4n+2),
+  pre.sourcelines.stripes > :nth-child(4n+3):hover + :nth-child(4n+4) { background-color:#edece6; }
   td { padding:2px 5px; font-size:12px; vertical-align:top; }
   td.closed { background-color: #99f; }
   td.link { padding:2px 5px; font-family:sans-serif; font-size:10px; }