[PATCH] cogito: Add cg-undo command

[PATCH] cogito: Add cg-undo command

[Matt Porter]

Adds a cg-undo command which takes a commit ID and resets HEAD
to the parent of the commit ID...refreshing the tree. This undoes
a single commit or a series of commits.

Signed-off-by: Matt Porter <mporter@kernel.crashing.org>

--- a1aff2a6748c0c0d08058c7d74503e724abc5d03/Makefile  (mode:100644 sha1:6ae0afa0208a8f755d383281a6d049a4ef90fe63)
+++ 023d9a7929d2f933d8e008f1679f13a58f7b1229/Makefile  (mode:100644 sha1:6c282aeebe86ecee9e634481b3d51fd53a582791)
@@ -47,7 +47,7 @@
 	cg-add cg-admin-lsobj cg-cancel cg-clone cg-commit cg-diff \
 	cg-export cg-help cg-init cg-log cg-ls cg-merge cg-mkpatch \
 	cg-patch cg-pull cg-branch-add cg-branch-ls cg-rm cg-seek cg-status \
-	cg-tag cg-tag-ls cg-update cg-Xlib
+	cg-tag cg-tag-ls cg-undo cg-update cg-Xlib
 
 COMMON=	read-cache.o
 
Index: cg-help
===================================================================
--- a1aff2a6748c0c0d08058c7d74503e724abc5d03/cg-help  (mode:100755 sha1:1f5d2d79b67490d44ce0f575ff9a4b80134ea47f)
+++ 023d9a7929d2f933d8e008f1679f13a58f7b1229/cg-help  (mode:100755 sha1:c7dc8f3e03895374cd0dae544570a37a459c2466)
@@ -43,6 +43,7 @@
 	cg-status
 	cg-tag		TNAME [COMMIT_ID]
 	cg-tag-ls
+	cg-undo		[COMMIT_ID]
 	cg-update	[BNAME]
 	cg-version
 
Index: cg-undo
===================================================================
--- /dev/null  (tree:a1aff2a6748c0c0d08058c7d74503e724abc5d03)
+++ 023d9a7929d2f933d8e008f1679f13a58f7b1229/cg-undo  (mode:100755 sha1:7fd6d89158fb5aeee42aa05a93f2c81884d9bd34)
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+#
+# Undo a commit or a series of commits
+# Copyright (C) Matt Porter, 2005
+#
+# Takes a commit ID which is the earliest commit to be
+# removed from the repository.
+
+. cg-Xlib
+
+PARENT=`git-cat-file commit $1 | grep parent | cut -f 2 -d " "`
+echo "Undo from $1 to current HEAD"
+echo "Reset HEAD to $PARENT"
+echo "$PARENT" > .git/HEAD
+git-read-tree -m "$PARENT" || {
+	echo >&2 "$PARENT: bad commit"
+	exit 1
+}
+git-checkout-cache -f -a
+git-update-cache --refresh

Re: [PATCH] cogito: Add cg-undo command

[Petr Baudis]

Dear diary, on Tue, May 03, 2005 at 07:06:25PM CEST, I got a letter
where Matt Porter <mporter@kernel.crashing.org> told me that...
> Index: cg-help
> ===================================================================
> --- a1aff2a6748c0c0d08058c7d74503e724abc5d03/cg-help  (mode:100755 sha1:1f5d2d79b67490d44ce0f575ff9a4b80134ea47f)
> +++ 023d9a7929d2f933d8e008f1679f13a58f7b1229/cg-help  (mode:100755 sha1:c7dc8f3e03895374cd0dae544570a37a459c2466)
> @@ -43,6 +43,7 @@
>  	cg-status
>  	cg-tag		TNAME [COMMIT_ID]
>  	cg-tag-ls
> +	cg-undo		[COMMIT_ID]

It doesn't seem very optional now.

>  	cg-update	[BNAME]
>  	cg-version
>  
> Index: cg-undo
> ===================================================================
> --- /dev/null  (tree:a1aff2a6748c0c0d08058c7d74503e724abc5d03)
> +++ 023d9a7929d2f933d8e008f1679f13a58f7b1229/cg-undo  (mode:100755 sha1:7fd6d89158fb5aeee42aa05a93f2c81884d9bd34)
> @@ -0,0 +1,20 @@
> +#!/usr/bin/env bash
> +#
> +# Undo a commit or a series of commits
> +# Copyright (C) Matt Porter, 2005
> +#
> +# Takes a commit ID which is the earliest commit to be
> +# removed from the repository.
> +
> +. cg-Xlib
> +
> +PARENT=`git-cat-file commit $1 | grep parent | cut -f 2 -d " "`

What's wrong with parent-id?

> +echo "Undo from $1 to current HEAD"
> +echo "Reset HEAD to $PARENT"

You talk way too much, I think. I'd just do

	echo "Rewinding $HEAD -> $PARENT" >&2

> +echo "$PARENT" > .git/HEAD
> +git-read-tree -m "$PARENT" || {
> +	echo >&2 "$PARENT: bad commit"
> +	exit 1
> +}
> +git-checkout-cache -f -a
> +git-update-cache --refresh

You really don't want to do this if the tree has any local
modifications.


Please make sure the commit you are rewinding to is an ancestor of your
current HEAD (there should be something like separate cg-branch-rm for
killing enemy branches).

-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor

Re: [PATCH] cogito: Add cg-undo command

[Matt Porter]

On Tue, May 03, 2005 at 11:32:04PM +0200, Petr Baudis wrote:
> Dear diary, on Tue, May 03, 2005 at 07:06:25PM CEST, I got a letter
> where Matt Porter <mporter@kernel.crashing.org> told me that...
> > +	cg-undo		[COMMIT_ID]
> 
> It doesn't seem very optional now.

Yep, changed.

> > +PARENT=`git-cat-file commit $1 | grep parent | cut -f 2 -d " "`
>
> What's wrong with parent-id?

Missed it...changed to use parent-id.

> > +echo "Undo from $1 to current HEAD"
> > +echo "Reset HEAD to $PARENT"
> 
> You talk way too much, I think. I'd just do
> 
> 	echo "Rewinding $HEAD -> $PARENT" >&2

Done.

> > +git-update-cache --refresh
> 
> You really don't want to do this if the tree has any local
> modifications.

Ugh, yes. I added a check for this. 

> Please make sure the commit you are rewinding to is an ancestor of your
> current HEAD (there should be something like separate cg-branch-rm for
> killing enemy branches).

Added a check for this as well as verifying we have an argument.
 
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>

--- aa6233be6d1b8bf42797c409a7c23b50593afc99/Makefile  (mode:100644 sha1:6ae0afa0208a8f755d383281a6d049a4ef90fe63)
+++ ce72371d991b15a0ca8db7c2332d215b59b909af/Makefile  (mode:100644 sha1:6c282aeebe86ecee9e634481b3d51fd53a582791)
@@ -47,7 +47,7 @@
 	cg-add cg-admin-lsobj cg-cancel cg-clone cg-commit cg-diff \
 	cg-export cg-help cg-init cg-log cg-ls cg-merge cg-mkpatch \
 	cg-patch cg-pull cg-branch-add cg-branch-ls cg-rm cg-seek cg-status \
-	cg-tag cg-tag-ls cg-update cg-Xlib
+	cg-tag cg-tag-ls cg-undo cg-update cg-Xlib
 
 COMMON=	read-cache.o
 
Index: cg-help
===================================================================
--- aa6233be6d1b8bf42797c409a7c23b50593afc99/cg-help  (mode:100755 sha1:1f5d2d79b67490d44ce0f575ff9a4b80134ea47f)
+++ ce72371d991b15a0ca8db7c2332d215b59b909af/cg-help  (mode:100755 sha1:1b75114ee90d2b3b9786fc4f14bf179feef54f87)
@@ -43,6 +43,7 @@
 	cg-status
 	cg-tag		TNAME [COMMIT_ID]
 	cg-tag-ls
+	cg-undo		COMMIT_ID
 	cg-update	[BNAME]
 	cg-version
 
Index: cg-undo
===================================================================
--- /dev/null  (tree:aa6233be6d1b8bf42797c409a7c23b50593afc99)
+++ ce72371d991b15a0ca8db7c2332d215b59b909af/cg-undo  (mode:100644 sha1:7b1cb04c79731b137d88ebd05ee41553af7246d2)
@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+#
+# Undo a commit or a series of commits
+# Copyright (C) Matt Porter, 2005
+#
+# Takes a commit ID which is the earliest commit to be
+# removed from the repository.
+
+. cg-Xlib
+
+[ "$1" ] || die "usage: cg-undo COMMIT_ID"
+
+HEAD=$(commit-id) || exit 1;
+PARENT=$(parent-id "$1") || exit 1;
+
+git-rev-list $HEAD | grep -q $1 || {
+	echo >&2 "$1: not an ancestor of HEAD"
+	exit 1
+}
+[ "$(git-diff-files -s)" ] && git-update-cache --refresh
+if [ "$(git-diff-files -s)" ] || [ "$(git-diff-cache $(tree-id))" ]; then
+        die "Undo blocked: local changes"
+fi
+
+echo "Rewinding HEAD -> $PARENT" >&2
+echo "$PARENT" > .git/HEAD
+git-read-tree -m "$PARENT" || {
+	echo >&2 "$PARENT: bad commit"
+	exit 1
+}
+git-checkout-cache -f -a
+git-update-cache --refresh

Re: [PATCH] cogito: Add cg-undo command

[Petr Baudis]

Dear diary, on Wed, May 04, 2005 at 07:40:07AM CEST, I got a letter
where Matt Porter <mporter@kernel.crashing.org> told me that...
> Signed-off-by: Matt Porter <mporter@kernel.crashing.org>

Thanks. I took it, hacked upon it for a while and then committed
something similar but largely rewritten as cg-admin-uncommit. ;-)

-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor