hgweb: show revisions and hashes gotten from changelog in "comparison" page

Before this patch, revision numbers and hash values in "comparison"
page are gotten from not changelog but filelog.

Such filelog information is useful only for hgweb debugging, and may
confuse users.

This patch shows revision numbers and hash values gotten from
changelog in "comparison" page.

mercurial/hgweb/webcommands.py

@@ -8,7 +8,7 b''
 import os, mimetypes, re, cgi, copy
 import webutil
 from mercurial import error, encoding, archival, templater, templatefilters
-from mercurial.node import short, hex, nullid
+from mercurial.node import short, hex
 from mercurial import util
 from common import paritygen, staticfile, get_contact, ErrorResponse
 from common import HTTP_OK, HTTP_FORBIDDEN, HTTP_NOT_FOUND
@@ -712,28 +712,22 b' def comparison(web, req, tmpl):'
             return [_('(binary file %s, hash: %s)') % (mt, hex(f.filenode()))]
         return f.data().splitlines()
 
+    parent = ctx.p1()
+    leftrev = parent.rev()
+    leftnode = parent.node()
+    rightrev = ctx.rev()
+    rightnode = ctx.node()
     if path in ctx:
         fctx = ctx[path]
-        rightrev = fctx.filerev()
-        rightnode = fctx.filenode()
         rightlines = filelines(fctx)
-        parent = ctx.p1()
         if path not in parent:
-            leftrev = -1
-            leftnode = nullid
             leftlines = ()
         else:
             pfctx = parent[path]
-            leftrev = pfctx.filerev()
-            leftnode = pfctx.filenode()
             leftlines = filelines(pfctx)
     else:
-        rightrev = -1
-        rightnode = nullid
         rightlines = ()
         fctx = ctx.parents()[0][path]
-        leftrev = fctx.filerev()
-        leftnode = fctx.filenode()
         leftlines = filelines(fctx)
 
     comparison = webutil.compare(tmpl, context, leftlines, rightlines)

tests/test-hgweb-diffs.t

@@ -576,6 +576,10 b' diff modified file'
 
 comparison new file
 
+  $ hg parents --template "{rev}:{node|short}\n" -r 0
+  $ hg log --template "{rev}:{node|short}\n" -r 0
+  0:0cd96de13884
+
   $ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'comparison/0/a'
   200 Script output follows
   
@@ -667,7 +671,7 b' comparison new file'
     <thead class="header">
       <tr>
         <th>-1:000000000000</th>
-        <th>0:b789fdd96dc2</th>
+        <th>0:0cd96de13884</th>
       </tr>
     </thead>
     
@@ -697,6 +701,12 b' comparison existing file'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo a >> a
   $ hg ci -mc
+
+  $ hg parents --template "{rev}:{node|short}\n" -r tip
+  1:559edbd9ed20
+  $ hg log --template "{rev}:{node|short}\n" -r tip
+  2:d73db4d812ff
+
   $ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'comparison/tip/a'
   200 Script output follows
   
@@ -787,8 +797,8 b' comparison existing file'
   <table class="bigtable">
     <thead class="header">
       <tr>
-        <th>0:b789fdd96dc2</th>
-        <th>1:a80d06849b33</th>
+        <th>1:559edbd9ed20</th>
+        <th>2:d73db4d812ff</th>
       </tr>
     </thead>
     
@@ -820,6 +830,12 b' comparison removed file'
 
   $ hg rm a
   $ hg ci -md
+
+  $ hg parents --template "{rev}:{node|short}\n" -r tip
+  2:d73db4d812ff
+  $ hg log --template "{rev}:{node|short}\n" -r tip
+  3:20e80271eb7a
+
   $ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'comparison/tip/a'
   200 Script output follows
   
@@ -910,8 +926,8 b' comparison removed file'
   <table class="bigtable">
     <thead class="header">
       <tr>
-        <th>1:a80d06849b33</th>
-        <th>-1:000000000000</th>
+        <th>2:d73db4d812ff</th>
+        <th>3:20e80271eb7a</th>
       </tr>
     </thead>
     
@@ -947,13 +963,13 b' comparison not-modified file'
   $ echo f > f
   $ hg add f
   $ hg ci -m f
-  $ hg tip --template "{node|short}\n"
-  41d9fc4a6ae1
+  $ hg tip --template "{rev}:{node|short}\n"
+  5:41d9fc4a6ae1
   $ hg diff -c tip e
-  $ hg parents --template "{node|short}\n" -r tip
-  402bea3b0976
-  $ hg parents --template "{node|short}\n" -r tip e
-  402bea3b0976
+  $ hg parents --template "{rev}:{node|short}\n" -r tip
+  4:402bea3b0976
+  $ hg parents --template "{rev}:{node|short}\n" -r tip e
+  4:402bea3b0976
 
   $ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'comparison/tip/e'
   200 Script output follows
@@ -1045,8 +1061,8 b' comparison not-modified file'
   <table class="bigtable">
     <thead class="header">
       <tr>
-        <th>0:6b67ccefd5ce</th>
-        <th>0:6b67ccefd5ce</th>
+        <th>4:402bea3b0976</th>
+        <th>5:41d9fc4a6ae1</th>
       </tr>
     </thead>