Merge branch 'lm/range-diff-submodule-fix'

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index 23dd04cbe864432f05f6fb91407dadb529dd075b..147201dc6c5786c9cfedbbbff0df0b1dced171db 100755 (executable)
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -541,6 +541,7 @@ copy_or_skip () {
        nonidentical=
        p=
        gotparents=
+       copycommit=
        for parent in $newparents
        do
                ptree=$(toptree_for_commit $parent) || exit $?
@@ -548,7 +549,24 @@ copy_or_skip () {
                if test "$ptree" = "$tree"
                then
                        # an identical parent could be used in place of this rev.
-                       identical="$parent"
+                       if test -n "$identical"
+                       then
+                               # if a previous identical parent was found, check whether
+                               # one is already an ancestor of the other
+                               mergebase=$(git merge-base $identical $parent)
+                               if test "$identical" = "$mergebase"
+                               then
+                                       # current identical commit is an ancestor of parent
+                                       identical="$parent"
+                               elif test "$parent" != "$mergebase"
+                               then
+                                       # no common history; commit must be copied
+                                       copycommit=1
+                               fi
+                       else
+                               # first identical parent detected
+                               identical="$parent"
+                       fi
                else
                        nonidentical="$parent"
                fi
@@ -571,7 +589,6 @@ copy_or_skip () {
                fi
        done
 
-       copycommit=
        if test -n "$identical" && test -n "$nonidentical"
        then
                extras=$(git rev-list --count $identical..$nonidentical)
@@ -616,7 +633,7 @@ process_split_commit () {
        else
                # processing commit without normal parent information;
                # fetch from repo
-               parents=$(git show -s --pretty=%P "$rev")
+               parents=$(git rev-parse "$rev^@")
                extracount=$(($extracount + 1))
        fi