Merge pull request #2213 from mtrmac/c-image-decompress-edits

Update after containers/image#2273

go.mod

@@ -4,7 +4,7 @@ go 1.19
 
 require (
 	github.com/containers/common v0.57.4
-	github.com/containers/image/v5 v5.29.3-0.20240131175401-a63f4a542670
+	github.com/containers/image/v5 v5.29.3-0.20240207231441-93b4b55d865b
 	github.com/containers/ocicrypt v1.1.9
 	github.com/containers/storage v1.52.0
 	github.com/docker/distribution v2.8.3+incompatible
@@ -17,7 +17,7 @@ require (
 	github.com/stretchr/testify v1.8.4
 	github.com/syndtr/gocapability v0.0.0-20200815063812-42c35b437635
 	golang.org/x/exp v0.0.0-20240119083558-1b970713d09a
-	golang.org/x/term v0.16.0
+	golang.org/x/term v0.17.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
@@ -39,7 +39,7 @@ require (
 	github.com/cyphar/filepath-securejoin v0.2.4 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/distribution/reference v0.5.0 // indirect
-	github.com/docker/docker v25.0.1+incompatible // indirect
+	github.com/docker/docker v25.0.3+incompatible // indirect
 	github.com/docker/docker-credential-helpers v0.8.1 // indirect
 	github.com/docker/go-connections v0.5.0 // indirect
 	github.com/docker/go-units v0.5.0 // indirect
@@ -72,21 +72,21 @@ require (
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/klauspost/compress v1.17.5 // indirect
+	github.com/klauspost/compress v1.17.6 // indirect
 	github.com/klauspost/pgzip v1.2.6 // indirect
 	github.com/letsencrypt/boulder v0.0.0-20230907030200-6d76a0f91e1e // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/mattn/go-shellwords v1.0.12 // indirect
-	github.com/mattn/go-sqlite3 v1.14.21 // indirect
+	github.com/mattn/go-sqlite3 v1.14.22 // indirect
 	github.com/miekg/pkcs11 v1.1.1 // indirect
 	github.com/mistifyio/go-zfs/v3 v3.0.1 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/moby/sys/mountinfo v0.7.1 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/oklog/ulid v1.3.1 // indirect
-	github.com/opencontainers/runc v1.1.11 // indirect
+	github.com/opencontainers/runc v1.1.12 // indirect
 	github.com/opencontainers/runtime-spec v1.1.0 // indirect
 	github.com/opencontainers/selinux v1.11.0 // indirect
 	github.com/opentracing/opentracing-go v1.2.0 // indirect
@@ -119,12 +119,12 @@ require (
 	go.opentelemetry.io/otel v1.19.0 // indirect
 	go.opentelemetry.io/otel/metric v1.19.0 // indirect
 	go.opentelemetry.io/otel/trace v1.19.0 // indirect
-	golang.org/x/crypto v0.18.0 // indirect
+	golang.org/x/crypto v0.19.0 // indirect
 	golang.org/x/mod v0.14.0 // indirect
 	golang.org/x/net v0.20.0 // indirect
 	golang.org/x/oauth2 v0.16.0 // indirect
 	golang.org/x/sync v0.6.0 // indirect
-	golang.org/x/sys v0.16.0 // indirect
+	golang.org/x/sys v0.17.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	golang.org/x/tools v0.17.0 // indirect
 	google.golang.org/appengine v1.6.8 // indirect

go.sum

@@ -36,8 +36,8 @@ github.com/containerd/stargz-snapshotter/estargz v0.15.1 h1:eXJjw9RbkLFgioVaTG+G
 github.com/containerd/stargz-snapshotter/estargz v0.15.1/go.mod h1:gr2RNwukQ/S9Nv33Lt6UC7xEx58C+LHRdoqbEKjz1Kk=
 github.com/containers/common v0.57.4 h1:kmfBad92kUjP5X44BPpOwMe+eZQqaKETfS+ASeL0g+g=
 github.com/containers/common v0.57.4/go.mod h1:o3L3CyOI9yr+JC8l4dZgvqTxcjs3qdKmkek00uchgvw=
-github.com/containers/image/v5 v5.29.3-0.20240131175401-a63f4a542670 h1:EjaG74rMIAv0icDhefI4DTnK4KY5gwBIlW/7lqvnBVQ=
-github.com/containers/image/v5 v5.29.3-0.20240131175401-a63f4a542670/go.mod h1:0OOeUAHBL3svD8r681/A0lY+XrwokWYH2Zcg7mhIS2s=
+github.com/containers/image/v5 v5.29.3-0.20240207231441-93b4b55d865b h1:SDiNbvEwiBB0TdoIBkfkY39FD1c2jzL3aJIXRsSr0oA=
+github.com/containers/image/v5 v5.29.3-0.20240207231441-93b4b55d865b/go.mod h1:hD2xTPHZ/QaNHhxx92ysHfy8OlrakkfkHQkaz4tD7Gs=
 github.com/containers/libtrust v0.0.0-20230121012942-c1716e8a8d01 h1:Qzk5C6cYglewc+UyGf6lc8Mj2UaPTHy/iF2De0/77CA=
 github.com/containers/libtrust v0.0.0-20230121012942-c1716e8a8d01/go.mod h1:9rfv8iPl1ZP7aqh9YA68wnZv2NUDbXdcdPHVz0pFbPY=
 github.com/containers/ocicrypt v1.1.9 h1:2Csfba4jse85Raxk5HIyEk8OwZNjRvfkhEGijOjIdEM=
@@ -57,11 +57,11 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/distribution/reference v0.5.0 h1:/FUIFXtfc/x2gpa5/VGfiGLuOIdYa1t65IKK2OFGvA0=
 github.com/distribution/reference v0.5.0/go.mod h1:BbU0aIcezP1/5jX/8MP0YiH4SdvB5Y4f/wlDRiLyi3E=
-github.com/docker/cli v25.0.1+incompatible h1:mFpqnrS6Hsm3v1k7Wa/BO23oz0k121MTbTO1lpcGSkU=
+github.com/docker/cli v25.0.3+incompatible h1:KLeNs7zws74oFuVhgZQ5ONGZiXUUdgsdy6/EsX/6284=
 github.com/docker/distribution v2.8.3+incompatible h1:AtKxIZ36LoNK51+Z6RpzLpddBirtxJnzDrHLEKxTAYk=
 github.com/docker/distribution v2.8.3+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
-github.com/docker/docker v25.0.1+incompatible h1:k5TYd5rIVQRSqcTwCID+cyVA0yRg86+Pcrz1ls0/frA=
-github.com/docker/docker v25.0.1+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/docker v25.0.3+incompatible h1:D5fy/lYmY7bvZa0XTZ5/UJPljor41F+vdyJG5luQLfQ=
+github.com/docker/docker v25.0.3+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
 github.com/docker/docker-credential-helpers v0.8.1 h1:j/eKUktUltBtMzKqmfLB0PAgqYyMHOp5vfsD1807oKo=
 github.com/docker/docker-credential-helpers v0.8.1/go.mod h1:P3ci7E3lwkZg6XiHdRKft1KckHiO9a2rNtyFbZ/ry9M=
 github.com/docker/go-connections v0.5.0 h1:USnMq7hx7gwdVZq1L49hLXaFtUdTADjXGp+uj1Br63c=
@@ -222,8 +222,8 @@ github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/klauspost/compress v1.4.1/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
 github.com/klauspost/compress v1.13.6/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
-github.com/klauspost/compress v1.17.5 h1:d4vBd+7CHydUqpFBgUEKkSdtSugf9YFmSkvUYPquI5E=
-github.com/klauspost/compress v1.17.5/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
+github.com/klauspost/compress v1.17.6 h1:60eq2E/jlfwQXtvZEeBUYADs+BwKBWURIY+Gj2eRGjI=
+github.com/klauspost/compress v1.17.6/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
 github.com/klauspost/cpuid v1.2.0/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
 github.com/klauspost/pgzip v1.2.6 h1:8RXeL5crjEUFnR2/Sn6GJNWtSQ3Dk8pq4CL3jvdDyjU=
 github.com/klauspost/pgzip v1.2.6/go.mod h1:Ch1tH69qFZu15pkjo5kYi6mth2Zzwzt50oCQKQE9RUs=
@@ -251,8 +251,8 @@ github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZ
 github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mattn/go-shellwords v1.0.12 h1:M2zGm7EW6UQJvDeQxo4T51eKPurbeFbe8WtebGE2xrk=
 github.com/mattn/go-shellwords v1.0.12/go.mod h1:EZzvwXDESEeg03EKmM+RmDnNOPKG4lLtQsUlTZDWQ8Y=
-github.com/mattn/go-sqlite3 v1.14.21 h1:IXocQLOykluc3xPE0Lvy8FtggMz1G+U3mEjg+0zGizc=
-github.com/mattn/go-sqlite3 v1.14.21/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
+github.com/mattn/go-sqlite3 v1.14.22 h1:2gZY6PC6kBnID23Tichd1K+Z0oS6nE/XwU+Vz/5o4kU=
+github.com/mattn/go-sqlite3 v1.14.22/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
 github.com/miekg/pkcs11 v1.1.1 h1:Ugu9pdy6vAYku5DEpVWVFPYnzV+bxB+iRdbuFSu7TvU=
 github.com/miekg/pkcs11 v1.1.1/go.mod h1:XsNlhZGX73bx86s2hdc/FuaLm2CPZJemRLMA+WTFxgs=
@@ -283,8 +283,8 @@ github.com/opencontainers/image-spec v1.1.0-rc6 h1:XDqvyKsJEbRtATzkgItUqBA7QHk58
 github.com/opencontainers/image-spec v1.1.0-rc6/go.mod h1:W4s4sFTMaBeK1BQLXbG4AdM2szdn85PY75RI83NrTrM=
 github.com/opencontainers/image-tools v1.0.0-rc3 h1:ZR837lBIxq6mmwEqfYrbLMuf75eBSHhccVHy6lsBeM4=
 github.com/opencontainers/image-tools v1.0.0-rc3/go.mod h1:A9btVpZLzttF4iFaKNychhPyrhfOjJ1OF5KrA8GcLj4=
-github.com/opencontainers/runc v1.1.11 h1:9LjxyVlE0BPMRP2wuQDRlHV4941Jp9rc3F0+YKimopA=
-github.com/opencontainers/runc v1.1.11/go.mod h1:S+lQwSfncpBha7XTy/5lBwWgm5+y5Ma/O44Ekby9FK8=
+github.com/opencontainers/runc v1.1.12 h1:BOIssBaW1La0/qbNZHXOOa71dZfZEQOzW7dqQf3phss=
+github.com/opencontainers/runc v1.1.12/go.mod h1:S+lQwSfncpBha7XTy/5lBwWgm5+y5Ma/O44Ekby9FK8=
 github.com/opencontainers/runtime-spec v1.1.0 h1:HHUyrt9mwHUjtasSbXSMvs4cyFxh+Bll4AjJ9odEGpg=
 github.com/opencontainers/runtime-spec v1.1.0/go.mod h1:jwyrGlmzljRJv/Fgzds9SsS/C5hL+LL3ko9hs6T5lQ0=
 github.com/opencontainers/selinux v1.11.0 h1:+5Zbo97w3Lbmb3PeqQtpmTkMwsW5nRI3YaLpt7tQ7oU=
@@ -429,8 +429,8 @@ golang.org/x/crypto v0.0.0-20200302210943-78000ba7a073/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
-golang.org/x/crypto v0.18.0 h1:PGVlW0xEltQnzFZ55hkuX5+KLyrMYhHld1YHO4AKcdc=
-golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1mg=
+golang.org/x/crypto v0.19.0 h1:ENy+Az/9Y1vSrlrvBSyna3PITt4tiZLf7sgCjZBX7Wo=
+golang.org/x/crypto v0.19.0/go.mod h1:Iy9bg/ha4yyC70EfRS8jz+B6ybOBKMaSxLj6P6oBDfU=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20240119083558-1b970713d09a h1:Q8/wZp0KX97QFTc2ywcOE0YRjZPVIx+MXInMzdvQqcA=
 golang.org/x/exp v0.0.0-20240119083558-1b970713d09a/go.mod h1:idGWGoKP1toJGkd5/ig9ZLuPcZBC3ewk7SzmH0uou08=
@@ -487,12 +487,12 @@ golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.16.0 h1:xWw16ngr6ZMtmxDyKyIgsE93KNKz5HKmMa3b8ALHidU=
-golang.org/x/sys v0.16.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.17.0 h1:25cE3gD+tdBA7lp7QfhuV+rJiE9YXTcS3VG1SqssI/Y=
+golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.16.0 h1:m+B6fahuftsE9qjo0VWp2FW0mB3MTJvR0BaMQrq0pmE=
-golang.org/x/term v0.16.0/go.mod h1:yn7UURbUtPyrVJPGPq404EukNFxcm/foM+bV/bfcDsY=
+golang.org/x/term v0.17.0 h1:mkTF7LCd6WGJNL3K1Ad7kwxNfYAW6a8a8QqtMblp/4U=
+golang.org/x/term v0.17.0/go.mod h1:lLRBjIVuehSbZlaOtGMbcMncT+aqLLLmKrsjNrUguwk=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=

integration/copy_test.go

@@ -187,7 +187,7 @@ func (s *copySuite) TestCopyWithManifestListStorage() {
 	assertSkopeoSucceeds(t, "", "copy", knownListImage, "containers-storage:"+storage+"test")
 	assertSkopeoSucceeds(t, "", "copy", knownListImage, "dir:"+dir1)
 	assertSkopeoSucceeds(t, "", "copy", "containers-storage:"+storage+"test", "dir:"+dir2)
-	runDecompressDirs(t, dir1, dir2)
+	decompressDirs(t, dir1, dir2)
 	assertDirImagesAreEqual(t, dir1, dir2)
 }
 
@@ -201,7 +201,7 @@ func (s *copySuite) TestCopyWithManifestListStorageMultiple() {
 	assertSkopeoSucceeds(t, "", "--override-arch", "arm64", "copy", knownListImage, "containers-storage:"+storage+"test")
 	assertSkopeoSucceeds(t, "", "--override-arch", "arm64", "copy", knownListImage, "dir:"+dir1)
 	assertSkopeoSucceeds(t, "", "copy", "containers-storage:"+storage+"test", "dir:"+dir2)
-	runDecompressDirs(t, dir1, dir2)
+	decompressDirs(t, dir1, dir2)
 	assertDirImagesAreEqual(t, dir1, dir2)
 }
 
@@ -248,7 +248,7 @@ func (s *copySuite) TestCopyWithManifestListStorageDigest() {
 	assertSkopeoSucceeds(t, "", "copy", knownListImage+"@"+digest, "containers-storage:"+storage+"test@"+digest)
 	assertSkopeoSucceeds(t, "", "copy", "containers-storage:"+storage+"test@"+digest, "dir:"+dir1)
 	assertSkopeoSucceeds(t, "", "copy", knownListImage+"@"+digest, "dir:"+dir2)
-	runDecompressDirs(t, dir1, dir2)
+	decompressDirs(t, dir1, dir2)
 	assertDirImagesAreEqual(t, dir1, dir2)
 }
 
@@ -265,7 +265,7 @@ func (s *copySuite) TestCopyWithManifestListStorageDigestMultipleArches() {
 	assertSkopeoSucceeds(t, "", "copy", knownListImage+"@"+digest, "containers-storage:"+storage+"test@"+digest)
 	assertSkopeoSucceeds(t, "", "copy", "containers-storage:"+storage+"test@"+digest, "dir:"+dir1)
 	assertSkopeoSucceeds(t, "", "copy", knownListImage+"@"+digest, "dir:"+dir2)
-	runDecompressDirs(t, dir1, dir2)
+	decompressDirs(t, dir1, dir2)
 	assertDirImagesAreEqual(t, dir1, dir2)
 }
 

integration/utils.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"bytes"
+	"compress/gzip"
+	"encoding/json"
 	"io"
 	"net"
 	"net/netip"
@@ -13,12 +15,12 @@ import (
 	"time"
 
 	"github.com/containers/image/v5/manifest"
+	"github.com/opencontainers/go-digest"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 const skopeoBinary = "skopeo"
-const decompressDirsBinary = "./decompress-dirs.sh"
 
 const testFQIN = "docker://quay.io/libpod/busybox" // tag left off on purpose, some tests need to add a special one
 const testFQIN64 = "docker://quay.io/libpod/busybox:amd64"
@@ -186,25 +188,98 @@ func fileFromFixture(t *testing.T, inputPath string, edits map[string]string) st
 	return path
 }
 
-// runDecompressDirs runs decompress-dirs.sh using exec.Command().CombinedOutput, verifies that the exit status is 0,
-// and optionally that the output matches a multi-line regexp if it is nonempty; or terminates c on failure
-func runDecompressDirs(t *testing.T, args ...string) {
-	t.Logf("Running %s %s", decompressDirsBinary, strings.Join(args, " "))
-	for i, dir := range args {
+// decompressDirs decompresses specified dir:-formatted directories
+func decompressDirs(t *testing.T, dirs ...string) {
+	t.Logf("Decompressing %s", strings.Join(dirs, " "))
+	for i, dir := range dirs {
 		m, err := os.ReadFile(filepath.Join(dir, "manifest.json"))
 		require.NoError(t, err)
 		t.Logf("manifest %d before: %s", i+1, string(m))
+
+		decompressDir(t, dir)
+
+		m, err = os.ReadFile(filepath.Join(dir, "manifest.json"))
+		require.NoError(t, err)
+		t.Logf("manifest %d after: %s", i+1, string(m))
 	}
-	out, err := exec.Command(decompressDirsBinary, args...).CombinedOutput()
-	assert.NoError(t, err, "%s", out)
-	for i, dir := range args {
-		if len(out) > 0 {
-			t.Logf("output: %s", out)
+}
+
+// getRawMapField assigns a value of rawMap[key] to dest,
+// failing if it does not exist or if it doesn’t have the expected type
+func getRawMapField[T any](t *testing.T, rawMap map[string]any, key string, dest *T) {
+	rawValue, ok := rawMap[key]
+	require.True(t, ok, key)
+	value, ok := rawValue.(T)
+	require.True(t, ok, key, "%#v", value)
+	*dest = value
+}
+
+// decompressDir modifies a dir:-formatted directory to replace gzip-compressed layers with uncompressed variants,
+// and to use a ~canonical formatting of manifest.json.
+func decompressDir(t *testing.T, dir string) {
+	// This is, overall, very dumb; the “obvious” way would be to invoke skopeo to decompress,
+	// or at least to use c/image to parse/format the manifest.
+	//
+	// But this is used to test (aspects of) those code paths… so, it’s acceptable for this to be
+	// dumb and to make assumptions about the data, but it should not share code.
+
+	manifestBlob, err := os.ReadFile(filepath.Join(dir, "manifest.json"))
+	require.NoError(t, err)
+	var rawManifest map[string]any
+	err = json.Unmarshal(manifestBlob, &rawManifest)
+	require.NoError(t, err)
+	var rawLayers []any
+	getRawMapField(t, rawManifest, "layers", &rawLayers)
+	for i, rawLayerValue := range rawLayers {
+		rawLayer, ok := rawLayerValue.(map[string]any)
+		require.True(t, ok)
+		var digestString string
+		getRawMapField(t, rawLayer, "digest", &digestString)
+		compressedDigest, err := digest.Parse(digestString)
+		require.NoError(t, err)
+		if compressedDigest.String() == "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855" { // An empty file
+			continue
 		}
-		m, err := os.ReadFile(filepath.Join(dir, "manifest.json"))
+
+		compressedPath := filepath.Join(dir, compressedDigest.Encoded())
+		compressedStream, err := os.Open(compressedPath)
 		require.NoError(t, err)
-		t.Logf("manifest %d after: %s", i+1, string(m))
+		defer compressedStream.Close()
+
+		uncompressedStream, err := gzip.NewReader(compressedStream)
+		if err != nil {
+			continue // Silently assume the layer is not gzip-compressed
+		}
+		tempDest, err := os.CreateTemp(dir, "decompressing")
+		require.NoError(t, err)
+		digester := digest.Canonical.Digester()
+		uncompressedSize, err := io.Copy(tempDest, io.TeeReader(uncompressedStream, digester.Hash()))
+		require.NoError(t, err)
+		err = uncompressedStream.Close()
+		require.NoError(t, err)
+		uncompressedDigest := digester.Digest()
+		uncompressedPath := filepath.Join(dir, uncompressedDigest.Encoded())
+		err = os.Rename(tempDest.Name(), uncompressedPath)
+		require.NoError(t, err)
+		err = os.Remove(compressedPath)
+		require.NoError(t, err)
+
+		rawLayer["digest"] = uncompressedDigest.String()
+		rawLayer["size"] = uncompressedSize
+		var mimeType string
+		getRawMapField(t, rawLayer, "mediaType", &mimeType)
+		if strings.HasSuffix(mimeType, ".gzip") { // This should use CutSuffix with Go ≥1.20
+			rawLayer["mediaType"] = strings.TrimSuffix(mimeType, ".gzip")
+		}
+
+		rawLayers[i] = rawLayer
 	}
+	rawManifest["layers"] = rawLayers
+
+	manifestBlob, err = json.Marshal(rawManifest)
+	require.NoError(t, err)
+	err = os.WriteFile(filepath.Join(dir, "manifest.json"), manifestBlob, 0o600)
+	require.NoError(t, err)
 }
 
 // Verify manifest in a dir: image at dir is expectedMIMEType.