[StGit PATCH] New command: stg redo

["Karl Hasselström" <kha@treskal.com>]

Command for undoing an undo.

Signed-off-by: Karl Hasselström <kha@treskal.com>

---

 stgit/commands/redo.py |   21 +++++++++------
 stgit/lib/log.py       |   19 ++++++++++----
 stgit/main.py          |    2 +
 t/t3104-redo.sh        |   66 +++++++++++++++++++++++++++++++++++++-----------
 4 files changed, 79 insertions(+), 29 deletions(-)
 copy stgit/commands/{undo.py => redo.py} (71%)
 copy t/{t3102-undo.sh => t3104-redo.sh} (53%)


diff --git a/stgit/commands/undo.py b/stgit/commands/redo.py
similarity index 71%
copy from stgit/commands/undo.py
copy to stgit/commands/redo.py
index b1d7de9..47221a5 100644
--- a/stgit/commands/undo.py
+++ b/stgit/commands/redo.py
@@ -19,28 +19,31 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 
 from optparse import make_option
 from stgit.commands import common
-from stgit.lib import git, log, transaction
-from stgit.out import out
+from stgit.lib import log, transaction
 
-help = 'undo the last operation'
+help = 'undo the last undo operation'
 usage = """%prog [options]
 
-Reset the patch stack to the previous state. Consecutive invocations
-of "stg undo" will take you ever further into the past."""
+If the last command was an undo, reset the patch stack to the state it
+had before the undo. Consecutive invocations of "stg redo" will undo
+the effects of consecutive invocations of "stg undo".
+
+It is an error to run "stg redo" if the last command was not an
+undo."""
 
 directory = common.DirectoryHasRepositoryLib()
 options = [make_option('-n', '--number', type = 'int', metavar = 'N',
                        default = 1,
-                       help = 'undo the last N commands'),
+                       help = 'undo the last N undos'),
            make_option('--hard', action = 'store_true',
                        help = 'discard changes in your index/worktree')]
 
 def func(parser, options, args):
     stack = directory.repository.current_stack
     if options.number < 1:
-        raise common.CmdException('Bad number of commands to undo')
-    state = log.undo_state(stack, options.number)
-    trans = transaction.StackTransaction(stack, 'undo %d' % options.number,
+        raise common.CmdException('Bad number of undos to redo')
+    state = log.undo_state(stack, -options.number)
+    trans = transaction.StackTransaction(stack, 'redo %d' % options.number,
                                          discard_changes = options.hard)
     try:
         log.reset_stack(trans, stack.repository.default_iw, state, [])
diff --git a/stgit/lib/log.py b/stgit/lib/log.py
index a82d4bc..d2a2ba7 100644
--- a/stgit/lib/log.py
+++ b/stgit/lib/log.py
@@ -243,13 +243,22 @@ def reset_stack(trans, iw, state, only_patches):
 def undo_state(stack, undo_steps):
     ref = log_ref(stack.name)
     log = Log(stack.repository, ref, stack.repository.refs.get(ref))
-    while undo_steps > 0:
+    while undo_steps != 0:
         msg = log.commit.data.message.strip()
-        m = re.match(r'^undo\s+(\d+)$', msg)
-        if m:
-            undo_steps += int(m.group(1))
+        um = re.match(r'^undo\s+(\d+)$', msg)
+        if undo_steps > 0:
+            if um:
+                undo_steps += int(um.group(1))
+            else:
+                undo_steps -= 1
         else:
-            undo_steps -= 1
+            rm = re.match(r'^redo\s+(\d+)$', msg)
+            if um:
+                undo_steps += 1
+            elif rm:
+                undo_steps -= int(rm.group(1))
+            else:
+                raise LogException('No more redo information available')
         if not log.parents:
             raise LogException('Not enough undo information available')
         log = Log(stack.repository, log.parents[0].sha1, log.parents[0])
diff --git a/stgit/main.py b/stgit/main.py
index cf7b404..c53abf7 100644
--- a/stgit/main.py
+++ b/stgit/main.py
@@ -86,6 +86,7 @@ commands = Commands({
     'pull':             'pull',
     'push':             'push',
     'rebase':           'rebase',
+    'redo':             'redo',
     'refresh':          'refresh',
     'rename':           'rename',
     'repair':           'repair',
@@ -123,6 +124,7 @@ stackcommands = (
     'pull',
     'push',
     'rebase',
+    'redo',
     'repair',
     'reset',
     'series',
diff --git a/t/t3102-undo.sh b/t/t3104-redo.sh
similarity index 53%
copy from t/t3102-undo.sh
copy to t/t3104-redo.sh
index 1093f70..290fc6f 100755
--- a/t/t3102-undo.sh
+++ b/t/t3104-redo.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_description='Simple test cases for "stg undo"'
+test_description='Simple test cases for "stg redo"'
 
 . ./test-lib.sh
 
@@ -20,18 +20,18 @@ test_expect_success 'Initialize StGit stack with three patches' '
     git commit -a -m p2 &&
     echo 333 >> a &&
     git commit -a -m p3 &&
-    stg uncommit -n 3 &&
-    stg pop
+    stg uncommit -n 3
 '
 
 cat > expected.txt <<EOF
 000
 111
+222
 EOF
 test_expect_success 'Pop one patch ...' '
     stg pop &&
-    test "$(echo $(stg applied))" = "p1" &&
-    test "$(echo $(stg unapplied))" = "p2 p3" &&
+    test "$(echo $(stg applied))" = "p1 p2" &&
+    test "$(echo $(stg unapplied))" = "p3" &&
     test_cmp expected.txt a
 '
 
@@ -39,9 +39,22 @@ cat > expected.txt <<EOF
 000
 111
 222
+333
 EOF
-test_expect_success '... and undo it' '
+test_expect_success '... undo it ...' '
     stg undo &&
+    test "$(echo $(stg applied))" = "p1 p2 p3" &&
+    test "$(echo $(stg unapplied))" = "" &&
+    test_cmp expected.txt a
+'
+
+cat > expected.txt <<EOF
+000
+111
+222
+EOF
+test_expect_success '... and redo' '
+    stg redo &&
     test "$(echo $(stg applied))" = "p1 p2" &&
     test "$(echo $(stg unapplied))" = "p3" &&
     test_cmp expected.txt a
@@ -50,7 +63,9 @@ test_expect_success '... and undo it' '
 cat > expected.txt <<EOF
 000
 EOF
-test_expect_success 'Pop two patches ...' '
+test_expect_success 'Pop three patches ...' '
+    stg push &&
+    stg pop &&
     stg pop &&
     stg pop &&
     test "$(echo $(stg applied))" = "" &&
@@ -62,24 +77,45 @@ cat > expected.txt <<EOF
 000
 111
 222
+333
 EOF
-test_expect_success '... and undo it' '
+test_expect_success '... undo it ...' '
     stg undo &&
     stg undo &&
-    test "$(echo $(stg applied))" = "p1 p2" &&
-    test "$(echo $(stg unapplied))" = "p3" &&
+    stg undo &&
+    test "$(echo $(stg applied))" = "p1 p2 p3" &&
+    test "$(echo $(stg unapplied))" = "" &&
     test_cmp expected.txt a
 '
 
 cat > expected.txt <<EOF
 000
 111
-222
 EOF
-test_expect_success 'Undo past end of history' '
-    ! stg undo -n 100 &&
-    test "$(echo $(stg applied))" = "p1 p2" &&
-    test "$(echo $(stg unapplied))" = "p3" &&
+test_expect_success '... redo the first two pops ...' '
+    stg redo -n 2 &&
+    test "$(echo $(stg applied))" = "p1" &&
+    test "$(echo $(stg unapplied))" = "p2 p3" &&
+    test_cmp expected.txt a
+'
+
+cat > expected.txt <<EOF
+000
+EOF
+test_expect_success '... and the remaining one' '
+    stg redo &&
+    test "$(echo $(stg applied))" = "" &&
+    test "$(echo $(stg unapplied))" = "p1 p2 p3" &&
+    test_cmp expected.txt a
+'
+
+cat > expected.txt <<EOF
+000
+EOF
+test_expect_success 'Redo past end of history' '
+    ! stg redo &&
+    test "$(echo $(stg applied))" = "" &&
+    test "$(echo $(stg unapplied))" = "p1 p2 p3" &&
     test_cmp expected.txt a
 '