[PATCH] hg diff --branch <branch>

[yozh at mx1.ru]

# HG changeset patch
# User Stepan Koltsov <stepancheg at yandex-team.ru>
# Date 1234400049 -10800
# Node ID 72971b249e72ff50c5426d1811e0a73399ac4400
# Parent  998fc8f62539ee26601d526803d6da2476129411
hg diff --branch <branch>
generate diff from the parent of the branch tail to the branch head

diff -r 998fc8f62539 -r 72971b249e72 mercurial/commands.py
--- a/mercurial/commands.py	Wed Jan 28 20:06:59 2009 -0600
+++ b/mercurial/commands.py	Thu Feb 12 03:54:09 2009 +0300
@@ -1028,13 +1028,36 @@
 
     revs = opts.get('rev')
     change = opts.get('change')
+    branch = opts.get('branch')
 
-    if revs and change:
-        msg = _('cannot specify --rev and --change at the same time')
+    if bool(revs) + bool(change) + bool(branch) > 1:
+        msg = _('cannot specify --rev, --change or --branch at the same time')
         raise util.Abort(msg)
     elif change:
         node2 = repo.lookup(change)
         node1 = repo[node2].parents()[0].node()
+    elif branch:
+        heads = {}
+        tails = {} # parents of first changests within branches
+        for rev in xrange(0, len(repo)):
+            c = repo[rev]
+            if c.branch() == branch:
+                for p in c.parents():
+                    if p.rev() in heads:
+                        del heads[p.rev()]
+                heads[c.rev()] = c
+                
+                for p in c.parents():
+                    if p.branch() != branch:
+                        tails[p.rev()] = p
+        def single(changesets, name):
+            if len(changets) == 0:
+                raise util.Abort(_(""))
+        if len(heads) != 1:
+            raise util.Abort(_("branch must have exactly one head"))
+        if len(tails) != 1:
+            raise util.Abort(_("branch must have exactly one parent of tail"))
+        node1, node2 = tails.itervalues().next().node(), heads.itervalues().next().node()
     else:
         node1, node2 = cmdutil.revpair(repo, revs)
 
@@ -3162,7 +3185,8 @@
     "^diff":
         (diff,
          [('r', 'rev', [], _('revision')),
-          ('c', 'change', '', _('change made by revision'))
+          ('c', 'change', '', _('change made by revision')),
+          ('', 'branch', '', _('diff from the tail to the head of the branch'))
          ] + diffopts + diffopts2 + walkopts,
          _('[OPTION]... [-r REV1 [-r REV2]] [FILE]...')),
     "^export":
diff -r 998fc8f62539 -r 72971b249e72 tests/test-diff-branch
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-diff-branch	Thu Feb 12 03:54:09 2009 +0300
@@ -0,0 +1,49 @@
+#!/bin/sh -e
+
+ec() {
+    echo "$@"
+    "$@"
+}
+
+echo "### Simple case"
+echo
+
+ec hg init r
+ec cd r
+
+echo "the quick brown fox" > file.txt
+hg add file.txt
+hg commit -m "first commit" # 0
+
+echo "jumps over the lazy dog" >> file.txt
+hg commit -m "second commit" # 1
+
+hg up 0 # just before second commit
+hg branch "rabbit"
+echo "and the rabbit rabbit" >> file.txt
+hg commit -m "into the rabbit branch" # 2
+
+ec hg diff --branch rabbit
+
+echo
+echo "### Complicating: single parent of two tails, head is merge"
+echo
+
+hg branch "complex"
+echo "to be or not to be" > shakespeare.txt
+hg add shakespeare.txt
+hg commit -m 'shakespeare' # 3
+echo "that is the question" >> shakespeare.txt
+hg commit -m 'shakespeare^2' # 4
+
+hg up 2
+hg branch --force "complex"
+echo "in god we trust" > file.txt
+hg commit -m "another head" # 5
+
+hg merge 4
+hg commit -m "merge two heads of the same branch"
+
+ec hg diff --branch "complex"
+
+# vim: set ts=4 sw=4 et:
diff -r 998fc8f62539 -r 72971b249e72 tests/test-diff-branch.out
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-diff-branch.out	Thu Feb 12 03:54:09 2009 +0300
@@ -0,0 +1,37 @@
+### Simple case
+
+hg init r
+cd r
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+marked working directory as branch rabbit
+created new head
+hg diff --branch rabbit
+diff -r 019d07f21017 -r 4c6087bd3384 file.txt
+--- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
++++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
+@@ -1,1 +1,2 @@
+ the quick brown fox
++and the rabbit rabbit
+
+### Complicating: single parent of two tails, head is merge
+
+marked working directory as branch complex
+0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+marked working directory as branch complex
+created new head
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+(branch merge, don't forget to commit)
+hg diff --branch complex
+diff -r 4c6087bd3384 -r 386f2ff150ae file.txt
+--- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
++++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
+@@ -1,2 +1,1 @@
+-the quick brown fox
+-and the rabbit rabbit
++in god we trust
+diff -r 4c6087bd3384 -r 386f2ff150ae shakespeare.txt
+--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
++++ b/shakespeare.txt	Thu Jan 01 00:00:00 1970 +0000
+@@ -0,0 +1,2 @@
++to be or not to be
++that is the question
diff -r 998fc8f62539 -r 72971b249e72 tests/test-help.out
--- a/tests/test-help.out	Wed Jan 28 20:06:59 2009 -0600
+++ b/tests/test-help.out	Thu Feb 12 03:54:09 2009 +0300
@@ -226,6 +226,7 @@
 
  -r --rev                  revision
  -c --change               change made by revision
+    --branch               diff from the tail to the head of the branch
  -a --text                 treat all files as text
  -g --git                  use git extended diff format
     --nodates              don't include dates in diff headers