Can we merge into the master branch but from one updated branch "A" and ignore other branches that were merged into A?

Question

From our master branch we created a new branch "1.5.5". From this 1.5.5 branch we created another branch "1.5.6". Different groups of developers are working on each of these branches. When we finished with 1.5.5, we merged it into 1.5.6.

Now we need to update the master branch. Would it be sufficient to just merge 1.5.6 into master? We don't need to merge 1.5.5 into master, correct?

Answer 1

The commits made to the 1.5.5 branch are in the 1.5.6 branch after the 1.5.5 branch were merged to the 1.5.6 branch.

When you merge the 1.5.6 branch to the master branch then all commits in the 1.5.6 branch will be merged into master regardless of which branch those commits were originally made to.

Answer 2

Correct, it's enough to merge 1.5.6 into master, because 1.5.6 has been merged with 1.5.5 too.