VSO git文件历史记录中的“简单历史记录（默认）”和“完整历史记录”有什么区别？

Question

In VSO git repository, on file history, there are filter options of 'Simple history(default)', 'First parent', 'Full history' and 'Full history(simplify merges). What's the difference among these options? and what's the difference between 'Simple history' and 'Full hisotry'.

We have like below commits showing in simple history. A--B--C--D--E--F But, after one of our developers run command "get reset --hard origin/develop", in Simple history, there are only commits A--B--C--D. E and F are missing. in 'Full history' we can still see commits A--B--C--D--E--F. the real problem, when run 'git pull' to pull latest code, we only get the code changes to commit D, and we cannot pull the code changes in E and F.

What should we do? so, we get E, F back in simple history, and when run 'git pull', code changes in E and F can be pulled to local disk.

Answer 1

Git history simplification can be a confusing beast. 99% of the time you won't even know it exists, but every once in a while it will jump out of the dark corners of Git and bite you. In this article we'll explore what history simplification is and how it can cause confusion when looking at file history.

Let's start with a common scenario:

You push a change to a file and then merge the change into master. Some of your colleagues also merge their branches to master. You come back some time later and notice your changes are missing. Looking for the culprit, you go look at the file history and notice... your changes aren't even listed!? What is happening here is that Git commit history is a tree, and sometimes the chronological history is not the same as the actual file tree history. This is particularly true in cases where a merge commit reverts a file back to its original state. In that case, the default history view won't actually show you all changes, because technically the file didn't change.

In the above scenario, Git realizes it can simplify the history and the "changes" you are most likely looking for are removed from the log.

Unless you have run into it before, the result is often a lot of hair pulling and wondering Where the heck did my changes go?

Source and more details: https://www.visualstudio.com/en-us/articles/git-log-history-simplification