Find merge commit which include a specific commit

git-get-merge will locate and show the merge commit you're looking for:

pip install git-get-merge
git get-merge <SHA-1>

The command follows the children of the given commit until a merge into another branch (presumably master) is found.

Add this to your ~/.gitconfig:

[alias]
    find-merge = "!sh -c 'commit=$0 && branch=${1:-HEAD} && (git rev-list $commit..$branch --ancestry-path | cat -n; git rev-list $commit..$branch --first-parent | cat -n) | sort -k2 -s | uniq -f1 -d | sort -n | tail -1 | cut -f2'"
    show-merge = "!sh -c 'merge=$(git find-merge $0 $1) && [ -n \"$merge\" ] && git show $merge'"

Then you can use the aliases like this:

# current branch
git find-merge <SHA-1>
# specify master
git find-merge <SHA-1> master

To see the merge commit's message and other details, use git show-merge with the same arguments.

(Based on Gauthier's answer. Thanks to Rosen Matev and javabrett for correcting a problem with sort.)

Your example shows that the branch feature is still available.

In that case h is the last result of:

git log master ^feature --ancestry-path

---

If the branch feature is not available anymore, you can show the merge commits in the history line between c and master:

git log <SHA-1_for_c>..master --ancestry-path --merges

This will however also show all the merges that happened after h, and between e and g on feature.

---

Comparing the result of the following commands:

git rev-list <SHA-1_for_c>..master --ancestry-path

git rev-list <SHA-1_for_c>..master --first-parent

will give you the SHA-1 of h as the last row in common.

If you have it available, you can use comm -1 -2 on these results. If you are on msysgit, you can use the following perl code to compare:

perl -ne 'print if ($seen{$_} .= @ARGV) =~ /10$/'  file1 file2

(perl code from http://www.cyberciti.biz/faq/command-to-display-lines-common-in-files/ , which took it from "someone at comp.unix.shell news group").

See process substitution if you want to make it a one-liner.