git stash: Give friendlier errors when there is nothing to apply

The change makes sure a stash (given or default) exists before
checking if the working tree is dirty.

If the default stash is requested, the old message was scary and
included a 'fatal' error from rev-parse:
     fatal: Needed a single revision
     : no valid stashed state found

It is replaced with a friendlier 'Nothing to apply' error, similar to
'git stash branch'.

If a specific stash is specified, the 'Needed a single revision' errors
from rev-parse are suppressed.

Signed-off-by: Ori Avtalion <ori@avtalion.name>
Acked-by: Thomas Rast <trast@student.ethz.ch>
Acked-by: Nanako Shiraishi <nanako3@lavabit.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-stash.sh b/git-stash.sh
index 03e589f764ba0570559fdb23a9a11cc2a0f24044..d61c9d03bc216cc2f1ab004fe3ffba42ef121a68 100755 (executable)
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -162,10 +162,6 @@ show_stash () {
 }
 
 apply_stash () {
-       git update-index -q --refresh &&
-       git diff-files --quiet --ignore-submodules ||
-               die 'Cannot apply to a dirty working tree, please stage your changes'
-
        unstash_index=
 
        while test $# != 0
@@ -184,18 +180,27 @@ apply_stash () {
                shift
        done
 
-       # current index state
-       c_tree=$(git write-tree) ||
-               die 'Cannot apply a stash in the middle of a merge'
+       if test $# = 0
+       then
+               have_stash || die 'Nothing to apply'
+       fi
 
        # 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 --verify --default $ref_stash "$@") &&
-       w_tree=$(git rev-parse --verify "$s:") &&
-       b_tree=$(git rev-parse --verify "$s^1:") &&
-       i_tree=$(git rev-parse --verify "$s^2:") ||
+       s=$(git rev-parse --quiet --verify --default $ref_stash "$@") &&
+       w_tree=$(git rev-parse --quiet --verify "$s:") &&
+       b_tree=$(git rev-parse --quiet --verify "$s^1:") &&
+       i_tree=$(git rev-parse --quiet --verify "$s^2:") ||
                die "$*: no valid stashed state found"
 
+       git update-index -q --refresh &&
+       git diff-files --quiet --ignore-submodules ||
+               die 'Cannot apply to a dirty working tree, please stage your changes'
+
+       # current index state
+       c_tree=$(git write-tree) ||
+               die 'Cannot apply a stash in the middle of a merge'
+
        unstashed_index_tree=
        if test -n "$unstash_index" && test "$b_tree" != "$i_tree" &&
                        test "$c_tree" != "$i_tree"