fetch: added support for named branches

fetch: added support for named branches

Previously, fetch didn't really work when there were multiple named branches
in the repository. Now it tries to do the right thing(tm) in all situations.

--- a/hgext/fetch.py	Mon Sep 08 12:55:27 2008 +0200
+++ b/hgext/fetch.py	Mon Sep 08 12:55:46 2008 +0200
@@ -16,7 +16,7 @@
     This finds all changes from the repository at the specified path
     or URL and adds them to the local repository.
 
-    If the pulled changes add a new head, the head is automatically
+    If the pulled changes add a new branch head, the head is automatically
     merged, and the result of the merge is committed.  Otherwise, the
     working directory is updated to include the new changes.
 
@@ -33,9 +33,10 @@
         opts['date'] = util.parsedate(date)
 
     parent, p2 = repo.dirstate.parents()
-    if parent != repo.changelog.tip():
-        raise util.Abort(_('working dir not at tip '
-                           '(use "hg update" to check out tip)'))
+    branch = repo[parent].branch()
+    if parent != repo[branch].node():
+        raise util.Abort(_('working dir not at branch tip '
+                           '(use "hg update" to check out branch tip)'))
 
     if p2 != nullid:
         raise util.Abort(_('outstanding uncommitted merge'))
@@ -50,9 +51,9 @@
             raise util.Abort(_('outstanding uncommitted changes'))
         if del_:
             raise util.Abort(_('working directory is missing some files'))
-        if len(repo.heads()) > 1:
-            raise util.Abort(_('multiple heads in this repository '
-                               '(use "hg heads" and "hg merge" to merge)'))
+        if len(repo.branchheads(branch)) > 1:
+            raise util.Abort(_('multiple heads in this branch '
+                               '(use "hg heads ." and "hg merge" to merge)'))
 
         cmdutil.setremoteconfig(ui, opts)
 
@@ -67,27 +68,35 @@
             else:
                 revs = [other.lookup(rev) for rev in opts['rev']]
 
+        # Are there any changes at all?
         modheads = repo.pull(other, heads=revs)
         if modheads == 0:
             return 0
-        if modheads == 1:
-            return hg.clean(repo, repo.changelog.tip())
 
-        newheads = repo.heads(parent)
-        newchildren = [n for n in repo.heads(parent) if n != parent]
+        # Is this a simple fast-forward along the current branch?
+        newheads = repo.branchheads(branch)
+        newchildren = repo.changelog.nodesbetween([parent], newheads)[2]
+        if len(newheads) == 1:
+            if newchildren[0] != parent:
+                return hg.clean(repo, newchildren[0])
+            else:
+                return
+
+        # Are there more than one additional branch heads?
+        newchildren = [n for n in newchildren if n != parent]
         newparent = parent
         if newchildren:
             newparent = newchildren[0]
             hg.clean(repo, newparent)
-
-        newheads = [n for n in repo.heads() if n != newparent]
+        newheads = [n for n in newheads if n != newparent]
         if len(newheads) > 1:
-            ui.status(_('not merging with %d other new heads '
-                        '(use "hg heads" and "hg merge" to merge them)') %
+            ui.status(_('not merging with %d other new branch heads '
+                        '(use "hg heads ." and "hg merge" to merge them)\n') %
                       (len(newheads) - 1))
             return
+
+        # Otherwise, let's merge.
         err = False
-
         if newheads:
             # By default, we consider the repository we're pulling
             # *from* as authoritative, so we merge our changes into

--- a/tests/test-fetch	Mon Sep 08 12:55:27 2008 +0200
+++ b/tests/test-fetch	Mon Sep 08 12:55:46 2008 +0200
@@ -7,6 +7,7 @@
 echo "[extensions]" >> $HGRCPATH
 echo "fetch=" >> $HGRCPATH
 
+echo % test fetch with default branches only
 hg init a
 echo a > a/a
 hg --cwd a commit -d '1 0' -Ama
@@ -66,4 +67,93 @@
 echo % should abort, because i is modified
 hg --cwd i fetch ../h
 
+
+echo % test fetch with named branches
+hg init nbase
+echo base > nbase/a
+hg -R nbase ci -d '1 0' -Am base
+hg -R nbase branch a
+echo a > nbase/a
+hg -R nbase ci -d '2 0' -m a
+hg -R nbase up -C 0
+hg -R nbase branch b
+echo b > nbase/b
+hg -R nbase ci -Ad '3 0' -m b
+
+echo
+echo % pull in change on foreign branch
+hg clone nbase n1
+hg clone nbase n2
+hg -R n1 up -C a
+echo aa > n1/a
+hg -R n1 ci -d '4 0' -m a1
+
+hg -R n2 up -C b
+hg -R n2 fetch -d '9 0' -m 'merge' n1
+echo '% parent should be 2 (no automatic update)'
+hg -R n2 parents --template '{rev}\n'
+rm -fr n1 n2
+
+echo
+echo % pull in changes on both foreign and local branches
+hg clone nbase n1
+hg clone nbase n2
+hg -R n1 up -C a
+echo aa > n1/a
+hg -R n1 ci -d '4 0' -m a1
+hg -R n1 up -C b
+echo bb > n1/b
+hg -R n1 ci -d '5 0' -m b1
+
+hg -R n2 up -C b
+hg -R n2 fetch -d '9 0' -m 'merge' n1
+echo '% parent should be 4 (fast forward)'
+hg -R n2 parents --template '{rev}\n'
+rm -fr n1 n2
+
+echo
+echo '% pull changes on foreign (2 new heads) and local (1 new head) branches'
+echo % with a local change
+hg clone nbase n1
+hg clone nbase n2
+hg -R n1 up -C a
+echo a1 > n1/a
+hg -R n1 ci -d '4 0' -m a1
+hg -R n1 up -C b
+echo bb > n1/b
+hg -R n1 ci -d '5 0' -m b1
+hg -R n1 up -C 1
+echo a2 > n1/a
+hg -R n1 ci -d '6 0' -m a2
+
+hg -R n2 up -C b
+echo change >> n2/c
+hg -R n2 ci -Ad '7 0' -m local
+hg -R n2 fetch -d '9 0' -m 'merge' n1
+echo '% parent should be 7 (new merge changeset)'
+hg -R n2 parents --template '{rev}\n'
+rm -fr n1 n2
+
+echo '% pull in changes on foreign (merge of local branch) and local (2 new'
+echo '% heads) with a local change'
+hg clone nbase n1
+hg clone nbase n2
+hg -R n1 up -C a
+hg -R n1 merge b
+hg -R n1 ci -d '4 0' -m merge
+hg -R n1 up -C 2
+echo c > n1/a
+hg -R n1 ci -d '5 0' -m c
+hg -R n1 up -C 2
+echo cc > n1/a
+hg -R n1 ci -d '6 0' -m cc
+
+hg -R n2 up -C b
+echo change >> n2/b
+hg -R n2 ci -Ad '7 0' -m local
+hg -R n2 fetch -d '9 0' -m 'merge' n1
+echo '% parent should be 3 (fetch did not merge anything)'
+hg -R n2 parents --template '{rev}\n'
+rm -fr n1 n2
+
 true

--- a/tests/test-fetch.out	Mon Sep 08 12:55:27 2008 +0200
+++ b/tests/test-fetch.out	Mon Sep 08 12:55:46 2008 +0200
@@ -1,3 +1,4 @@
+% test fetch with default branches only
 adding a
 updating working directory
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
@@ -79,3 +80,93 @@
 new changeset 4:55aa4f32ec59 merges remote changes with local
 % should abort, because i is modified
 abort: working directory is missing some files
+% test fetch with named branches
+adding a
+marked working directory as branch a
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+marked working directory as branch b
+adding b
+created new head
+
+% pull in change on foreign branch
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+pulling from n1
+searching for changes
+adding changesets
+adding manifests
+adding file changes
+added 1 changesets with 1 changes to 1 files
+% parent should be 2 (no automatic update)
+2
+
+% pull in changes on both foreign and local branches
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+pulling from n1
+searching for changes
+adding changesets
+adding manifests
+adding file changes
+added 2 changesets with 2 changes to 2 files
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+% parent should be 4 (fast forward)
+4
+
+% pull changes on foreign (2 new heads) and local (1 new head) branches
+% with a local change
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+created new head
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+adding c
+pulling from n1
+searching for changes
+adding changesets
+adding manifests
+adding file changes
+added 3 changesets with 3 changes to 2 files (+2 heads)
+updating to 5:708c6cce3d26
+1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+merging with 3:d83427717b1f
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+new changeset 7:48f1a33f52af merges remote changes with local
+% parent should be 7 (new merge changeset)
+7
+% pull in changes on foreign (merge of local branch) and local (2 new
+% heads) with a local change
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+updating working directory
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+(branch merge, don't forget to commit)
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+created new head
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+created new head
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+pulling from n1
+searching for changes
+adding changesets
+adding manifests
+adding file changes
+added 3 changesets with 2 changes to 1 files (+2 heads)
+not merging with 1 other new branch heads (use "hg heads ." and "hg merge" to merge them)
+% parent should be 3 (fetch did not merge anything)
+3