git squash commits
key words: git squash 删除 压缩 commit 提交
起因
在做新功能测试的时候在开发分支（branch dev）上创建了一个新的分支（branch dev_experiment)，在dev_experiment中做了很多尝试了，做了较多的提交，有些提交是中间过程，commit message也写的比较草率，不适合并入remote repo中，所以需要删除一些commit信息。
但是commit是不能删除的，只能压缩（squash）也就是,将多个commits合并成一个commit，这样提交记录就比较干净了。
用法
git rebase -i commit_hash^
NOTE: commit_hash^中的^用于指示是从该commit到HEAD
然后弹出编辑界面，如下。
pick 9ca62a2 commit_msg_xxxxxxxx
pick da462a1 commit_msg_yyyyyyyy
...
pick da462a1 commit_msg_zzzzzzzz
# Commands:
# p, pick <commit> = use commit
# r, reword <commit> = use commit, but edit the commit message
# e, edit <commit> = use commit, but stop for amending
# s, squash <commit> = use commit, but meld into previous commit
# f, fixup <commit> = like "squash", but discard this commit's log message
# x, exec <command> = run command (the rest of the line) using shell
# b, break = stop here (continue rebase later with 'git rebase --continue')
# d, drop <commit> = remove commit
# l, label <label> = label current HEAD with a name
# t, reset <label> = reset HEAD to a label
# m, merge [-C <commit> | -c <commit>] <label> [# <oneline>]
# . create a merge commit using the original merge commit's
# . message (or the oneline, if no original merge commit was
# . specified). Use -c <commit> to reword the commit message.
比如说我想将9ca62a2和da462a1合并，那就要将pick da462a1 commit_msg_yyyyyyyy改成squash da462a1 commit_msg_yyyyyyyy.
NOTE: 都是向上合并的# s, squash <commit> = use commit, but meld into previous commit