log: make -fr show complete history from the given revs

Right now it's very obtuse to show the history of a particular rev (hg log -r
'reverse(::foo)'). This changes the -f option to make it follow history for the
revs specified by -r.

The current -f -r behavior is to limit the result of -r to only the
commits that are ancestors of the current working copy. Changing this
is a bit of a BC break, but the old behavior is A) rare, B) easy to
emulate (& ::.), and C) currently undefined. The new behavior is
frequently requested enough that I think the change is worth it.

mercurial/commands.py

@@ -4478,6 +4478,10 b' def log(ui, repo, *pats, **opts):'
     Returns 0 on success.
 
     """
+    if opts.get('follow') and opts.get('rev'):
+        opts['rev'] = [revset.formatspec('reverse(::%lr)', opts.get('rev'))]
+        del opts['follow']
+
     if opts.get('graph'):
         return cmdutil.graphlog(ui, repo, *pats, **opts)
 

tests/test-glog.t

@@ -2202,13 +2202,6 b' Test --follow and forward --rev'
       (func
         ('symbol', 'rev')
         ('symbol', '6'))))
-  --- log.nodes	* (glob)
-  +++ glog.nodes	* (glob)
-  @@ -1,3 +1,3 @@
-  -nodetag 6
-   nodetag 8
-   nodetag 7
-  +nodetag 6
 
 Test --follow-first and forward --rev
 

tests/test-log.t

@@ -631,7 +631,7 b' log -f'
   
 
 
-log -f -r 1:tip
+log -f -r '1 + 4'
 
   $ hg up -C 0
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
@@ -639,24 +639,23 b' log -f -r 1:tip'
   $ hg ci -Amb2 -d '1 0'
   adding b2
   created new head
-  $ hg log -f -r 1:tip
+  $ hg log -f -r '1 + 4'
+  changeset:   4:ddb82e70d1a1
+  tag:         tip
+  parent:      0:67e992f2c4f3
+  user:        test
+  date:        Thu Jan 01 00:00:01 1970 +0000
+  summary:     b2
+  
   changeset:   1:3d5bf5654eda
   user:        test
   date:        Thu Jan 01 00:00:01 1970 +0000
   summary:     r1
   
-  changeset:   2:60c670bf5b30
+  changeset:   0:67e992f2c4f3
   user:        test
   date:        Thu Jan 01 00:00:01 1970 +0000
-  summary:     r2
-  
-  changeset:   3:e62f78d544b4
-  parent:      1:3d5bf5654eda
-  user:        test
-  date:        Thu Jan 01 00:00:01 1970 +0000
-  summary:     b1
-  
-
+  summary:     base
 
 log -f -r null
 
@@ -1346,6 +1345,11 b' Also check when maxrev < lastrevfilelog'
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     add foo, related
   
+  changeset:   2:c4c64aedf0f7
+  user:        test
+  date:        Thu Jan 01 00:00:00 1970 +0000
+  summary:     add unrelated old foo
+  
   $ cd ..
 
 Issue2383: hg log showing _less_ differences than hg diff