Merge of the pull request is overwriting the changes which were committed from previous pull request

[chandre gowda]

I have an issue observed multiple times in my project.  whenever we merge the pull request from one branch into master , the changes from previous pull request merge got overwritten even though overwritten files had no changes in latest pull request. 

Steps to reproduce.

1.  Created branch from master , then committed changes and created a pull request A. This has 2 file changes f1, f2.  

2.  Created another branch from master , then committed changes and created a pull request B. This has 2 file changes f3, f4.  

3.  Merged pull request A.

4. Merged pull request B. This overwrites files changes from pull request A. Now the master contains only f3 and f4. f1 an df2 are missing.

This  happens only for certain commits and not for all. Is there any setting that  needs to be done so that we can avoid overwriting of file changes. 

[Aman_Jain_lamresearch_com]

Same issue. Can someone from Atlassian please provide any answers.