merging

git checkout <master_branch>
git merge <branch to be merged>
do a commit and push via git gui



There are basically two ways to merge 
1) merge and resolve all the merge conflicts in the merge commit - especially for bigger changes like here this makes it quite hard to see in git commits what has changed - and how it revers to the different merged commits - all differences are hiding in the one huge merge commit 
2) revert conflicting changes, do a clean merge (no conflicts) reapply the conflicting stuff 

You used 1 
I had some discussions with more experienced gatekeepers in the past and they generally recommend to only use the second approach - for maintenance reasons 
Therefore I did so when merging the other ECM changes to certhandler 

Please give the pattern 2 a try. 
For the moment do this on a different devel branch to see and test if the pattern works for you. 
That way you can always switch back to the current devel branch or use it for comparison. 

Please have a look into adit_master how merges from ECM to certhandler branch have been done in the past. 
For example changes of SWGIII-38291 could be merged cleanly without any revert 
For merging SECWPK-778/779 (from sdcecm_v1.x_j06) to certhandler I had to revert most of the commits for SECWPK-778 - SECWPK-779 commit didn't need to be reverted 
These revert commits have some commit message telling that it is reverted for clean merge and that it will be reapplied (see 274ff7089e9696ddc54679dea8e64b3b273990a3 for an example) 
After the clean merge the changes are reapplied (e.g. 274ff7089e9696ddc54679dea8e64b3b273990a3) 
Also there the commit has some extra text
 (Adjust ebc92d1dd89efd08fd657089e19eeb16469a2308 to certhandler version)
    Signed-off-by: Christoph Gellner <cgellner@de.adit-jv.com>
telling that it is an adjusted and reapplied version of another commit 

What I usually do is trying to merge the commits one by one to identify which commits are causing troubles - just to identify conflicts 
Then I switch back to the branch I want to merge and revert those problematic commits and adjust the commit messages of the reverts accordingly - I try to keep the reverted commits in the reversed order of the original commits 
Afterwards I can do a clean merge - but conflicting changes are missing at this point in time (e.g. f66938c90c2d2d7971af59ccde09a09304dad250) 
Finally I reapply (cherry pick) the commits I previously reverted, resolve conflicts during cherry pick and adjust the commit message