migrate Podman to containers/common/libimage

Migrate the Podman code base over to `common/libimage` which replaces
`libpod/image` and a lot of glue code entirely.

Note that I tried to leave bread crumbs for changed tests.

Miscellaneous changes:

 * Some errors yield different messages which required to alter some
   tests.

 * I fixed some pre-existing issues in the code.  Others were marked as
   `//TODO`s to prevent the PR from exploding.

 * The `NamesHistory` of an image is returned as is from the storage.
   Previously, we did some filtering which I think is undesirable.
   Instead we should return the data as stored in the storage.

 * Touched handlers use the ABI interfaces where possible.

 * Local image resolution: previously Podman would match "foo" on
   "myfoo".  This behaviour has been changed and Podman will now
   only match on repository boundaries such that "foo" would match
   "my/foo" but not "myfoo".  I consider the old behaviour to be a
   bug, at the very least an exotic corner case.

 * Futhermore, "foo:none" does *not* resolve to a local image "foo"
   without tag anymore.  It's a hill I am (almost) willing to die on.

 * `image prune` prints the IDs of pruned images.  Previously, in some
   cases, the names were printed instead.  The API clearly states ID,
   so we should stick to it.

 * Compat endpoint image removal with _force_ deletes the entire not
   only the specified tag.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/pkg/errorhandling/errorhandling.go b/pkg/errorhandling/errorhandling.go
index 9dc545ebb..9b1740006 100644
--- a/pkg/errorhandling/errorhandling.go
+++ b/pkg/errorhandling/errorhandling.go
@@ -33,6 +33,9 @@ func JoinErrors(errs []error) error {
 // ErrorsToString converts the slice of errors into a slice of corresponding
 // error messages.
 func ErrorsToStrings(errs []error) []string {
+	if len(errs) == 0 {
+		return nil
+	}
 	strErrs := make([]string, len(errs))
 	for i := range errs {
 		strErrs[i] = errs[i].Error()
@@ -43,6 +46,9 @@ func ErrorsToStrings(errs []error) []string {
 // StringsToErrors converts a slice of error messages into a slice of
 // corresponding errors.
 func StringsToErrors(strErrs []string) []error {
+	if len(strErrs) == 0 {
+		return nil
+	}
 	errs := make([]error, len(strErrs))
 	for i := range strErrs {
 		errs[i] = errors.New(strErrs[i])