1 files changed, 40 insertions, 0 deletions
diff --git a/libexec/find-base-commits.sh b/libexec/find-base-commits.sh
new file mode 100755
index 0000000..3e16227
--- /dev/null
+++ b/libexec/find-base-commits.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+
+extend_bases () {
+  shas="$1"
+  new="$2"
+  for sha in $shas ; do
+    [ "$sha" = "$new" ] && continue
+    ${DELI_GIT_IS_ANCESTOR_CMD:-git merge-base --is-ancestor} "$sha" "$new"
+    res=$?
+    case $res in
+    0) ;;
+    1) echo "$sha" ;;
+    *) echo "$0: ancestor finding failed" >&2
+       exit 1 ;;
+    esac
+  done
+  old=no
+  for sha in $shas ; do
+    [ "$sha" = "$new" ] && continue
+    ${DELI_GIT_IS_ANCESTOR_CMD:-git merge-base --is-ancestor} "$new" "$sha"
+    res=$?
+    case $res in
+    0) old=yes ; break ;;
+    1) ;;
+    *) echo "$0: ancestor finding failed" >&2
+       exit 1 ;;
+    esac
+  done
+  [ $old = no ] && echo "$new"
+}
+
+bases=""
+
+while read sha ; do
+  bases=$( extend_bases "$bases" "$sha" )
+done
+
+for sha in $bases ; do
+  echo "$sha"
+done