The website need hide some menu items under developing, by comment out the html codes (at line 19~24 in file "client/comTemp.html"). But last night we found they reappeared in the newest version. Apparently someone used the older version (in which they were not commented out) overwrite the latest version by error (without intention).
How to find out who, at which commit make this mistake?
Step 1: get the error version.
$ git blame -L 19,24 client/comTemp.html
dc7d385a (Tom 2015-06-26 17:39:28 +0800 19) <li>
8b64184a (Bob 2015-05-04 19:32:43 +0800 20) <a href="/mall">Mall</a>
6bb3ba70 (Franky 2015-05-04 15:45:50 +0800 21) </li>
6bb3ba70 (Franky 2015-05-04 15:45:50 +0800 22) <li>
8b64184a (Bob 2015-05-04 19:32:43 +0800 23) <a href="/services">Services</a>
dc7d385a (Tom 2015-06-26 17:39:28 +0800 24) </li>
Here the line 19 should be <!--<li> and line 24 should be </li>-->,
to hide "Mall" and "Services", which are under developing.
Step 2: get the newest right version.
The wrong commit is "dc7d385a", so we have to find the nearest change before it:
$ git blame -L 19,24 'dc7d385a^' -- client/comTemp.html
96269db1 (Bob 2015-06-10 15:36:31 +0800 19) <!--<li>
8b64184a (Bob 2015-05-04 19:32:43 +0800 20) <a href="/mall">Mall</a>
6bb3ba70 (Franky 2015-05-04 15:45:50 +0800 21) </li>
6bb3ba70 (Franky 2015-05-04 15:45:50 +0800 22) <li>
8b64184a (Bob 2015-05-04 19:32:43 +0800 23) <a href="/services">Services</a>
96269db1 (Bob 2015-06-10 15:36:31 +0800 24) </li>-->
So we know Mall and Services were commented out at commit 96269db1, 2015-06-10, and uncommented by error at commit dc7d385a, 2015-06-26, by Tom.
Step 3: show code changes.
$ git show dc7d385a -- client/comTemp.htm
...
- <!--<li>
+ <li>
<a href="/mall">Mall</a>
</li>
<li>
<a href="/services">Services</a>
- </li>-->
+ </li>
...
It shows in commit dc7d385a, two lines were deleted: "", while two lines were added: "
Step 4 (optional): revert the commit
git revert dc7d385a
Ref: http://stackoverflow.com/questions/14836696/delete-last-commit-in-bitbucket