status: don't say 'HEAD detached at HEAD'

diff --git a/git-am.sh b/git-am.sh
index a67d0f98989706fa69df4cf7d6242ad9531eb337..3103c0fc28910560d85f4c2cff2b6a0595848b16 100755 (executable)
--- a/git-am.sh
+++ b/git-am.sh
@@ -69,6 +69,8 @@ then
        cmdline="$cmdline -3"
 fi
 
+empty_tree=4b825dc642cb6eb9a060e54bf8d69288fbee4904
+
 sq () {
        git rev-parse --sq-quote "$@"
 }
@@ -85,7 +87,7 @@ safe_to_abort () {
                return 1
        fi
 
-       if ! test -s "$dotest/abort-safety"
+       if ! test -f "$dotest/abort-safety"
        then
                return 0
        fi
@@ -177,7 +179,8 @@ It does not apply to blobs recorded in its index.")"
     then
            GIT_MERGE_VERBOSITY=0 && export GIT_MERGE_VERBOSITY
     fi
-    git-merge-recursive $orig_tree -- HEAD $his_tree || {
+    our_tree=$(git rev-parse --verify -q HEAD || echo $empty_tree)
+    git-merge-recursive $orig_tree -- $our_tree $his_tree || {
            git rerere $allow_rerere_autoupdate
            die "$(gettext "Failed to merge in the changes.")"
     }
@@ -502,10 +505,11 @@ then
                ;;
        t,)
                git rerere clear
-               git read-tree --reset -u HEAD HEAD
-               orig_head=$(cat "$GIT_DIR/ORIG_HEAD")
-               git reset HEAD
-               git update-ref ORIG_HEAD $orig_head
+               head_tree=$(git rev-parse --verify -q HEAD || echo $empty_tree) &&
+               git read-tree --reset -u $head_tree $head_tree &&
+               index_tree=$(git write-tree) &&
+               git read-tree -m -u $index_tree $head_tree
+               git read-tree $head_tree
                ;;
        ,t)
                if test -f "$dotest/rebasing"
@@ -515,8 +519,19 @@ then
                git rerere clear
                if safe_to_abort
                then
-                       git read-tree --reset -u HEAD ORIG_HEAD
-                       git reset ORIG_HEAD
+                       head_tree=$(git rev-parse --verify -q HEAD || echo $empty_tree) &&
+                       git read-tree --reset -u $head_tree $head_tree &&
+                       index_tree=$(git write-tree) &&
+                       orig_head=$(git rev-parse --verify -q ORIG_HEAD || echo $empty_tree) &&
+                       git read-tree -m -u $index_tree $orig_head
+                       if git rev-parse --verify -q ORIG_HEAD >/dev/null 2>&1
+                       then
+                               git reset ORIG_HEAD
+                       else
+                               git read-tree $empty_tree
+                               curr_branch=$(git symbolic-ref HEAD 2>/dev/null) &&
+                               git update-ref -d $curr_branch
+                       fi
                fi
                rm -fr "$dotest"
                exit ;;