subtree: more consistent error propagation

Ensure that every $(subshell) that calls a function (as opposed to an
external executable) is followed by `|| exit $?`.  Similarly, ensure that
every `cmd | while read; do ... done` loop is followed by `|| exit $?`.

Both of those constructs mean that it can miss `die` calls, and keep
running when it shouldn't.

Signed-off-by: Luke Shumaker <lukeshu@datawire.io>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index d1ed7f9a6ce016c9fca2189c6c4f94b510c0b124..9ca498f81c9d81ea3d5931c2d41d5f4d7b720303 100755 (executable)
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -243,7 +243,7 @@ cache_miss () {
 }
 
 check_parents () {
-       missed=$(cache_miss "$1")
+       missed=$(cache_miss "$1") || exit $?
        local indent=$(($2 + 1))
        for miss in $missed
        do
@@ -345,7 +345,7 @@ find_latest_squash () {
                        sub=
                        ;;
                esac
-       done
+       done || exit $?
 }
 
 find_existing_splits () {
@@ -394,7 +394,7 @@ find_existing_splits () {
                        sub=
                        ;;
                esac
-       done
+       done || exit $?
 }
 
 copy_commit () {
@@ -508,7 +508,7 @@ subtree_for_commit () {
                test "$type" = "commit" && continue  # ignore submodules
                echo $tree
                break
-       done
+       done || exit $?
 }
 
 tree_changed () {
@@ -518,7 +518,7 @@ tree_changed () {
        then
                return 0   # weird parents, consider it changed
        else
-               ptree=$(toptree_for_commit $1)
+               ptree=$(toptree_for_commit $1) || exit $?
                if test "$ptree" != "$tree"
                then
                        return 0   # changed
@@ -652,7 +652,7 @@ process_split_commit () {
        progress "$revcount/$revmax ($createcount) [$extracount]"
 
        debug "Processing commit: $rev"
-       exists=$(cache_get "$rev")
+       exists=$(cache_get "$rev") || exit $?
        if test -n "$exists"
        then
                debug "  prior: $exists"
@@ -661,10 +661,10 @@ process_split_commit () {
        createcount=$(($createcount + 1))
        debug "  parents: $parents"
        check_parents "$parents" "$indent"
-       newparents=$(cache_get $parents)
+       newparents=$(cache_get $parents) || exit $?
        debug "  newparents: $newparents"
 
-       tree=$(subtree_for_commit "$rev" "$dir")
+       tree=$(subtree_for_commit "$rev" "$dir") || exit $?
        debug "  tree is: $tree"
 
        # ugly.  is there no better way to tell if this is a subtree
@@ -750,7 +750,7 @@ cmd_add_commit () {
                commit=$(add_squashed_msg "$rev" "$dir" |
                        git commit-tree "$tree" $headp -p "$rev") || exit $?
        else
-               revp=$(peel_committish "$rev") &&
+               revp=$(peel_committish "$rev") || exit $?
                commit=$(add_msg "$dir" $headrev "$rev" |
                        git commit-tree "$tree" $headp -p "$revp") || exit $?
        fi
@@ -773,10 +773,10 @@ cmd_split () {
                        # any parent we find there can be used verbatim
                        debug "  cache: $rev"
                        cache_set "$rev" "$rev"
-               done
+               done || exit $?
        fi
 
-       unrevs="$(find_existing_splits "$dir" "$revs")"
+       unrevs="$(find_existing_splits "$dir" "$revs")" || exit $?
 
        # We can't restrict rev-list to only $dir here, because some of our
        # parents have the $dir contents the root, and those won't match.
@@ -792,7 +792,7 @@ cmd_split () {
                process_split_commit "$rev" "$parents" 0
        done || exit $?
 
-       latest_new=$(cache_get latest_new)
+       latest_new=$(cache_get latest_new) || exit $?
        if test -z "$latest_new"
        then
                die "No new revisions were found"
@@ -801,7 +801,7 @@ cmd_split () {
        if test -n "$rejoin"
        then
                debug "Merging split branch into HEAD..."
-               latest_old=$(cache_get latest_old)
+               latest_old=$(cache_get latest_old) || exit $?
                git merge -s ours \
                        --allow-unrelated-histories \
                        -m "$(rejoin_msg "$dir" "$latest_old" "$latest_new")" \
@@ -834,7 +834,7 @@ cmd_merge () {
 
        if test -n "$squash"
        then
-               first_split="$(find_latest_squash "$dir")"
+               first_split="$(find_latest_squash "$dir")" || exit $?
                if test -z "$first_split"
                then
                        die "Can't squash-merge: '$dir' was never added."