Clean up different special *HEAD handling

We codify the following different heads (in addition to the main "HEAD",
which points to the current branch, of course):

 - FETCH_HEAD

   Populated by "git fetch"

 - ORIG_HEAD

   The old HEAD before a "git pull/resolve" (successful or not)

 - LAST_MERGE

   The HEAD we're currently merging in "git pull/resolve"

 - MERGE_HEAD

   The previous head of a unresolved "git pull", which gets committed by
   a "git commit" after manually resolving the result

We used to have "MERGE_HEAD" be populated directly by the fetch, and we
removed ORIG_HEAD and LAST_MERGE too aggressively.

diff --git a/git-fetch-script b/git-fetch-script
index 7cd88b9..2e62f00 100755 (executable)
--- a/git-fetch-script
+++ b/git-fetch-script
@@ -35,7 +35,7 @@ download_objects () {
 }
 
 echo "Getting remote $merge_name"
-download_one "$merge_repo/$merge_name" "$GIT_DIR"/MERGE_HEAD || exit 1
+download_one "$merge_repo/$merge_name" "$GIT_DIR"/FETCH_HEAD || exit 1
 
 echo "Getting object database"
-download_objects "$merge_repo" "$(cat "$GIT_DIR"/MERGE_HEAD)" || exit 1
+download_objects "$merge_repo" "$(cat "$GIT_DIR"/FETCH_HEAD)" || exit 1

diff --git a/git-pull-script b/git-pull-script
index dbef56c..90ee0f3 100755 (executable)
--- a/git-pull-script
+++ b/git-pull-script
@@ -17,5 +17,5 @@ git-fetch-script "$merge_repo" "$merge_head" || exit 1
 
 git-resolve-script \
        "$(cat "$GIT_DIR"/HEAD)" \
-       "$(cat "$GIT_DIR"/MERGE_HEAD)" \
+       "$(cat "$GIT_DIR"/FETCH_HEAD)" \
        "$merge_name"

diff --git a/git-resolve-script b/git-resolve-script
index 91b001b..bf2fb2d 100755 (executable)
--- a/git-resolve-script
+++ b/git-resolve-script
@@ -12,7 +12,7 @@ merge_repo="$3"
 : ${GIT_OBJECT_DIRECTORY="${SHA1_FILE_DIRECTORY-"$GIT_DIR/objects"}"}
 
 dropheads() {
-       rm -f -- "$GIT_DIR/ORIG_HEAD" "$GIT_DIR/MERGE_HEAD" \
+       rm -f -- "$GIT_DIR/MERGE_HEAD" \
                "$GIT_DIR/LAST_MERGE" || exit 1
 }
 
@@ -44,7 +44,7 @@ if [ "$common" == "$head" ]; then
        echo "Updating from $head to $merge."
        git-read-tree -u -m $head $merge || exit 1
        echo $merge > "$GIT_DIR"/HEAD
-       git-diff-tree -p ORIG_HEAD HEAD | git-apply --stat
+       git-diff-tree -p $head $merge | git-apply --stat
        dropheads
        exit 0
 fi