[PATCH 1 of 6] rebase: improve error message for more than one external parent

[Pierre-Yves David]

On 23 oct. 2013, at 19:54, Mads Kiilerich wrote:

> # HG changeset patch
> # User Mads Kiilerich <madski at unity3d.com>
> # Date 1382542933 -28800
> #      Wed Oct 23 23:42:13 2013 +0800
> # Branch stable
> # Node ID 9c9093febeb627dca63bc30c7ecf515feaea5c24
> # Parent  b7f76db06dc0f1c85f05256eaba7ac7559e811e9
> rebase: improve error message for more than one external parent

This is hardly an improvement. I agree that the initial message is a bit cryptic, but your new version is just wrong.

>   $ hg rebase -s 2 --collapse
> -  abort: unable to collapse, there is more than one external parent
> +  abort: unable to collapse, there is more than one external parent to 1

We start from:

@  7: 'H' 
|
| o    6: 'G' 
| |\
| | o  5: 'F' 
| | | 
| | o  4: 'E' 
| | | 
| o |  3: 'D' 
| |\| 
| o |  2: 'C' 
|/ /
| o  1: 'B' 
|/
o  0: 'A' 

And we try to rebase+collapse 2:: (2,3,6) on 7. And we can't because the result would have three parents (7, 1 and 5)

The new message: abort: unable to collapse, there is more than one external parent to 1
- Wrongly present 1 as part of the rebased set,
- Does not list the actual issue (more than 2 parents to the result 7, 1 and 5)

(note: the example would be better if 5 was not a descendants of 1. I believe we could have rebase working in this situation.)

-- 
Pierre-Yves David