hgweb: add block numbers to diff regions and related links

The changeset view may show several diff regions, one per file, and this patch
numbers each of them so that links produced by the filenodelink fragment can
reference each diff region produced by the diffblock fragment through the use
of the blockno variable made available to both of them. This permits
navigation to diff regions on the changeset page from the file list, and
where the :target pseudo-class is supported in browsers, permits selective
presentation of diffs, showing one at a time instead of potentially many in
what would otherwise be a very long page that is difficult to navigate.

mercurial/hgweb/webcommands.py

@@ -262,10 +262,10 @@ def changeset(web, req, tmpl):
 
     files = []
     parity = paritygen(web.stripecount)
-    for f in ctx.files():
+    for blockno, f in enumerate(ctx.files()):
         template = f in ctx and 'filenodelink' or 'filenolink'
         files.append(tmpl(template,
-                          node=ctx.hex(), file=f,
+                          node=ctx.hex(), file=f, blockno=blockno + 1,
                           parity=parity.next()))
 
     style = web.config('web', 'style', 'paper')

mercurial/hgweb/webutil.py

@@ -173,8 +173,7 @@ def diffs(repo, tmpl, ctx, files, parity, style):
             start += 1
 
     blockcount = countgen()
-    def prettyprintlines(diff):
-        blockno = blockcount.next()
+    def prettyprintlines(diff, blockno):
         for lineno, l in enumerate(diff.splitlines(True)):
             lineno = "%d.%d" % (blockno, lineno + 1)
             if l.startswith('+'):
@@ -203,14 +202,16 @@ def diffs(repo, tmpl, ctx, files, parity, style):
     block = []
     for chunk in patch.diff(repo, node1, node2, m, opts=diffopts):
         if chunk.startswith('diff') and block:
-            yield tmpl('diffblock', parity=parity.next(),
-                       lines=prettyprintlines(''.join(block)))
+            blockno = blockcount.next()
+            yield tmpl('diffblock', parity=parity.next(), blockno=blockno,
+                       lines=prettyprintlines(''.join(block), blockno))
             block = []
         if chunk.startswith('diff') and style != 'raw':
             chunk = ''.join(chunk.splitlines(True)[1:])
         block.append(chunk)
-    yield tmpl('diffblock', parity=parity.next(),
-               lines=prettyprintlines(''.join(block)))
+    blockno = blockcount.next()
+    yield tmpl('diffblock', parity=parity.next(), blockno=blockno,
+               lines=prettyprintlines(''.join(block), blockno))
 
 def diffstatgen(ctx):
     '''Generator function that provides the diffstat data.'''

tests/test-hgweb-diffs.t

@@ -552,6 +552,51 @@ test import rev as raw-rev
   $ cd test1
   $ hg import -q --exact http://localhost:$HGPORT/rev/1
 
+raw revision with diff block numbers
+
+  $ "$TESTDIR/killdaemons.py"
+  $ cat <<EOF > .hg/hgrc
+  > [web]
+  > templates = rawdiff
+  > EOF
+  $ mkdir rawdiff
+  $ cat <<EOF > rawdiff/map
+  > mimetype = 'text/plain; charset={encoding}'
+  > changeset = '{diff}'
+  > difflineplus = '{line}'
+  > difflineminus = '{line}'
+  > difflineat = '{line}'
+  > diffline = '{line}'
+  > filenodelink = ''
+  > filenolink = ''
+  > fileline = '{line}'
+  > diffblock = 'Block: {blockno}\n{lines}\n'
+  > EOF
+  $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
+  $ cat hg.pid >> $DAEMON_PIDS
+  $ "$TESTDIR/get-with-headers.py" localhost:$HGPORT '/raw-rev/0'
+  200 Script output follows
+  
+  Block: 1
+  diff -r 000000000000 -r 0cd96de13884 a
+  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
+  @@ -0,0 +1,1 @@
+  +a
+  
+  Block: 2
+  diff -r 000000000000 -r 0cd96de13884 b
+  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/b	Thu Jan 01 00:00:00 1970 +0000
+  @@ -0,0 +1,1 @@
+  +b
+  
+  $ "$TESTDIR/killdaemons.py"
+  $ rm .hg/hgrc rawdiff/map
+  $ rmdir rawdiff
+  $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
+  $ cat hg.pid >> $DAEMON_PIDS
+
 errors
 
   $ cat ../test/errors.log