diff-delta.c: Rationalize culling of hash buckets

diff --git a/git-stash.sh b/git-stash.sh
index 777d1e13515960e20e50efa8eeb05289b8d225fb..30425ce6df8b8da9b105fa7d8e958936420983ed 100755 (executable)
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -3,8 +3,10 @@
 
 USAGE='[ | list | show | apply | clear]'
 
+SUBDIRECTORY_OK=Yes
 . git-sh-setup
 require_work_tree
+cd_to_toplevel
 
 TMP="$GIT_DIR/.git-stash.$$"
 trap 'rm -f "$TMP-*"' 0
@@ -17,12 +19,15 @@ no_changes () {
 }
 
 clear_stash () {
-       logfile="$GIT_DIR/logs/$ref_stash" &&
-       mkdir -p "$(dirname "$logfile")" &&
-       : >"$logfile"
+       if current=$(git rev-parse --verify $ref_stash 2>/dev/null)
+       then
+               git update-ref -d refs/stash $current
+       fi
 }
 
 save_stash () {
+       stash_msg="$1"
+
        if no_changes
        then
                echo >&2 'No local changes to save'
@@ -31,6 +36,9 @@ save_stash () {
        test -f "$GIT_DIR/logs/$ref_stash" ||
                clear_stash || die "Cannot initialize stash"
 
+       # Make sure the reflog for stash is kept.
+       : >>"$GIT_DIR/logs/$ref_stash"
+
        # state of the base commit
        if b_commit=$(git rev-parse --verify HEAD)
        then
@@ -55,11 +63,11 @@ save_stash () {
 
        # state of the working tree
        w_tree=$( (
+               rm -f "$TMP-index" &&
+               cp -p ${GIT_INDEX_FILE-"$GIT_DIR/index"} "$TMP-index" &&
                GIT_INDEX_FILE="$TMP-index" &&
                export GIT_INDEX_FILE &&
-
-               rm -f "$TMP-index" &&
-               git read-tree $i_tree &&
+               git read-tree -m $i_tree &&
                git add -u &&
                git write-tree &&
                rm -f "$TMP-index"
@@ -67,13 +75,19 @@ save_stash () {
                die "Cannot save the current worktree state"
 
        # create the stash
-       w_commit=$(printf 'WIP on %s' "$msg" |
+       if test -z "$stash_msg"
+       then
+               stash_msg=$(printf 'WIP on %s' "$msg")
+       else
+               stash_msg=$(printf 'On %s: %s' "$branch" "$stash_msg")
+       fi
+       w_commit=$(printf '%s\n' "$stash_msg" |
                git commit-tree $w_tree -p $b_commit -p $i_commit) ||
                die "Cannot record working tree state"
 
-       git update-ref -m "$msg" $ref_stash $w_commit ||
+       git update-ref -m "$stash_msg" $ref_stash $w_commit ||
                die "Cannot save the current status"
-       printf >&2 'Saved WIP on %s\n' "$msg"
+       printf >&2 'Saved "%s"\n' "$stash_msg"
 }
 
 have_stash () {
@@ -103,15 +117,36 @@ apply_stash () {
        git diff-files --quiet ||
                die 'Cannot restore on top of a dirty state'
 
+       unstash_index=
+       case "$1" in
+       --index)
+               unstash_index=t
+               shift
+       esac
+
        # current index state
        c_tree=$(git write-tree) ||
                die 'Cannot apply a stash in the middle of a merge'
 
+       # stash records the work tree, and is a merge between the
+       # base commit (first parent) and the index tree (second parent).
        s=$(git rev-parse --revs-only --no-flags --default $ref_stash "$@") &&
        w_tree=$(git rev-parse --verify "$s:") &&
-       b_tree=$(git rev-parse --verify "$s^:") ||
+       b_tree=$(git rev-parse --verify "$s^1:") &&
+       i_tree=$(git rev-parse --verify "$s^2:") ||
                die "$*: no valid stashed state found"
 
+       unstashed_index_tree=
+       if test -n "$unstash_index" && test "$b_tree" != "$i_tree"
+       then
+               git diff --binary $s^2^..$s^2 | git apply --cached
+               test $? -ne 0 &&
+                       die 'Conflicts in index. Try without --index.'
+               unstashed_index_tree=$(git-write-tree) ||
+                       die 'Could not save index tree'
+               git reset
+       fi
+
        eval "
                GITHEAD_$w_tree='Stashed changes' &&
                GITHEAD_$c_tree='Updated upstream' &&
@@ -122,23 +157,33 @@ apply_stash () {
        if git-merge-recursive $b_tree -- $c_tree $w_tree
        then
                # No conflict
-               a="$TMP-added" &&
-               git diff --cached --name-only --diff-filter=A $c_tree >"$a" &&
-               git read-tree --reset $c_tree &&
-               git update-index --add --stdin <"$a" ||
-                       die "Cannot unstage modified files"
-               git-status
-               rm -f "$a"
+               if test -n "$unstashed_index_tree"
+               then
+                       git read-tree "$unstashed_index_tree"
+               else
+                       a="$TMP-added" &&
+                       git diff --cached --name-only --diff-filter=A $c_tree >"$a" &&
+                       git read-tree --reset $c_tree &&
+                       git update-index --add --stdin <"$a" ||
+                               die "Cannot unstage modified files"
+                       rm -f "$a"
+               fi
+               git status || :
        else
                # Merge conflict; keep the exit status from merge-recursive
-               exit
+               status=$?
+               if test -n "$unstash_index"
+               then
+                       echo >&2 'Index was not unstashed.'
+               fi
+               exit $status
        fi
 }
 
 # Main command set
 case "$1" in
-list | '')
-       test $# -gt 0 && shift
+list)
+       shift
        if test $# = 0
        then
                set x -n 10
@@ -157,9 +202,14 @@ apply)
 clear)
        clear_stash
        ;;
-save)
-       save_stash && git-reset --hard
+help | usage)
+       usage
        ;;
 *)
-       usage
+       if test $# -gt 0 && test "$1" = save
+       then
+               shift
+       fi
+       save_stash "$*" && git-reset --hard
+       ;;
 esac