A shepherd for your Appimages.
preserve app icon extensions
Aly Raffauf
(Jun 19, 2026, 1:09 PM EDT)
92e46aa5
4fda6a24
+153
-15
+3
-3
internal/appherder/desktop.go
+3
-3
internal/appherder/desktop.go
···
55
55
return apps, nil
56
56
}
57
57
58
-
func (a App) patchDesktopFile(desktop *desktopfile.File, appName string, hasIcon bool) error {
58
+
func (a App) patchDesktopFile(desktop *desktopfile.File, appName string, iconPath string) error {
59
59
appimage := filepath.Join(a.appimagesDir, appName+".appimage")
60
60
61
61
desktop.Set(desktopEntrySection, desktopOwnerKey, "true")
62
-
if hasIcon {
63
-
desktop.Set(desktopEntrySection, "Icon", filepath.Join(a.iconsDir, appName))
62
+
if iconPath != "" {
63
+
desktop.Set(desktopEntrySection, "Icon", iconPath)
64
64
}
65
65
desktop.Set(desktopEntrySection, "TryExec", appimage)
66
66
+6
-5
internal/appherder/desktop_test.go
+6
-5
internal/appherder/desktop_test.go
···
25
25
`
26
26
27
27
func TestPatchDesktopFilePreservesDesktopActions(t *testing.T) {
28
-
a, home := newTestApp(t)
28
+
app, home := newTestApp(t)
29
29
30
30
desktop := desktopfile.Parse([]byte(sampleDesktopFile))
31
-
if err := a.patchDesktopFile(desktop, "example", true); err != nil {
31
+
iconPath := filepath.Join(home, "AppImages", ".icons", "example.png")
32
+
if err := app.patchDesktopFile(desktop, "example", iconPath); err != nil {
32
33
t.Fatal(err)
33
34
}
34
35
35
36
assertDesktopValue(t, desktop, desktopEntrySection, desktopOwnerKey, "true")
36
-
assertDesktopValue(t, desktop, desktopEntrySection, "Icon", filepath.Join(home, "AppImages", ".icons", "example"))
37
+
assertDesktopValue(t, desktop, desktopEntrySection, "Icon", iconPath)
37
38
assertDesktopValue(t, desktop, desktopEntrySection, "TryExec", filepath.Join(home, "AppImages", "example.appimage"))
38
39
assertDesktopExec(t, desktop, desktopEntrySection, []string{"env", "FOO=bar", "DESKTOPINTEGRATION=1", filepath.Join(home, "AppImages", "example.appimage"), "%U"})
39
40
assertDesktopExec(t, desktop, "Desktop Action new-window", []string{"env", "DESKTOPINTEGRATION=1", filepath.Join(home, "AppImages", "example.appimage"), "--new-window", "%U"})
···
96
97
}
97
98
98
99
func TestPatchDesktopFileSetsExecWhenMissing(t *testing.T) {
99
-
a, home := newTestApp(t)
100
+
app, home := newTestApp(t)
100
101
desktop := desktopfile.Parse([]byte(
101
102
"[Desktop Entry]\nType=Application\nName=Foo\nTerminal=true\n",
102
103
))
103
-
if err := a.patchDesktopFile(desktop, "foo", false); err != nil {
104
+
if err := app.patchDesktopFile(desktop, "foo", ""); err != nil {
104
105
t.Fatal(err)
105
106
}
106
107
assertDesktopValue(t, desktop, desktopEntrySection, "Terminal", "true")
+61
-4
internal/appherder/icons.go
+61
-4
internal/appherder/icons.go
···
1
1
package appherder
2
2
3
3
import (
4
+
"bytes"
4
5
"fmt"
5
6
"io/fs"
6
7
"os"
···
78
79
}
79
80
}
80
81
82
+
type iconInstall struct {
83
+
source string
84
+
path string
85
+
content []byte
86
+
}
87
+
81
88
func (a App) installIcon(fsys fs.FS, icon string, appName string) (string, error) {
89
+
preparedIcon, err := a.prepareIconInstall(fsys, icon, appName)
90
+
if err != nil {
91
+
return "", err
92
+
}
93
+
return a.installPreparedIcon(preparedIcon, appName)
94
+
}
95
+
96
+
func (a App) prepareIconInstall(fsys fs.FS, icon string, appName string) (iconInstall, error) {
97
+
content, err := fs.ReadFile(fsys, icon)
98
+
if err != nil {
99
+
return iconInstall{}, fmt.Errorf("read icon %s: %w", icon, err)
100
+
}
101
+
ext := iconExt(icon, content)
102
+
if ext == "" {
103
+
return iconInstall{}, fmt.Errorf("unsupported icon format %s", icon)
104
+
}
105
+
return iconInstall{
106
+
source: icon,
107
+
path: filepath.Join(a.iconsDir, appName+ext),
108
+
content: content,
109
+
}, nil
110
+
}
111
+
112
+
func (a App) installPreparedIcon(preparedIcon iconInstall, appName string) (string, error) {
82
113
if err := os.MkdirAll(a.iconsDir, 0o755); err != nil {
83
114
return "", fmt.Errorf("create icon directory %s: %w", a.iconsDir, err)
84
115
}
116
+
if err := writeIfChanged(preparedIcon.path, 0o644, preparedIcon.content); err != nil {
117
+
return "", fmt.Errorf("install icon %s to %s: %w", preparedIcon.source, preparedIcon.path, err)
118
+
}
119
+
for _, path := range a.installedIconPaths(appName) {
120
+
if path != preparedIcon.path {
121
+
_ = os.Remove(path)
122
+
}
123
+
}
124
+
_ = os.Remove(filepath.Join(a.iconsDir, appName))
125
+
return preparedIcon.path, nil
126
+
}
85
127
86
-
dest := filepath.Join(a.iconsDir, appName)
87
-
if err := copyFromFS(fsys, icon, dest); err != nil {
88
-
return "", fmt.Errorf("install icon %s to %s: %w", icon, dest, err)
128
+
func iconExt(name string, content []byte) string {
129
+
switch strings.ToLower(path.Ext(name)) {
130
+
case ".svg":
131
+
return ".svg"
132
+
case ".png":
133
+
return ".png"
134
+
case ".xpm":
135
+
return ".xpm"
89
136
}
90
-
return dest, nil
137
+
if bytes.HasPrefix(content, []byte("\x89PNG\r\n\x1a\n")) {
138
+
return ".png"
139
+
}
140
+
head := bytes.ToLower(bytes.TrimSpace(content[:min(len(content), 1024)]))
141
+
if bytes.Contains(head, []byte("<svg")) {
142
+
return ".svg"
143
+
}
144
+
if bytes.HasPrefix(head, []byte("/* xpm */")) {
145
+
return ".xpm"
146
+
}
147
+
return ""
91
148
}
+59
internal/appherder/icons_test.go
+59
internal/appherder/icons_test.go
···
1
1
package appherder
2
2
3
3
import (
4
+
"os"
5
+
"path/filepath"
4
6
"testing"
5
7
"testing/fstest"
6
8
)
···
65
67
t.Fatalf("resolveIcon = %q, want empty", got)
66
68
}
67
69
}
70
+
71
+
func TestInstallIconPreservesExtension(t *testing.T) {
72
+
app, home := newTestApp(t)
73
+
fsys := fstest.MapFS{
74
+
"keepassxc.png": {Data: []byte("\x89PNG\r\n\x1a\npng")},
75
+
}
76
+
77
+
got, err := app.installIcon(fsys, "keepassxc.png", "keepassxc")
78
+
if err != nil {
79
+
t.Fatal(err)
80
+
}
81
+
82
+
want := filepath.Join(home, "AppImages", ".icons", "keepassxc.png")
83
+
if got != want {
84
+
t.Fatalf("installIcon = %q, want %q", got, want)
85
+
}
86
+
}
87
+
88
+
func TestInstallIconDetectsDirIconPNG(t *testing.T) {
89
+
app, home := newTestApp(t)
90
+
fsys := fstest.MapFS{
91
+
".DirIcon": {Data: []byte("\x89PNG\r\n\x1a\npng")},
92
+
}
93
+
94
+
got, err := app.installIcon(fsys, ".DirIcon", "keepassxc")
95
+
if err != nil {
96
+
t.Fatal(err)
97
+
}
98
+
99
+
want := filepath.Join(home, "AppImages", ".icons", "keepassxc.png")
100
+
if got != want {
101
+
t.Fatalf("installIcon = %q, want %q", got, want)
102
+
}
103
+
}
104
+
105
+
func TestInstallIconRemovesStaleSiblings(t *testing.T) {
106
+
app, home := newTestApp(t)
107
+
iconDir := filepath.Join(home, "AppImages", ".icons")
108
+
if err := os.MkdirAll(iconDir, 0o755); err != nil {
109
+
t.Fatal(err)
110
+
}
111
+
stale := filepath.Join(iconDir, "keepassxc.svg")
112
+
if err := os.WriteFile(stale, []byte("<svg/>"), 0o644); err != nil {
113
+
t.Fatal(err)
114
+
}
115
+
fsys := fstest.MapFS{
116
+
"keepassxc.png": {Data: []byte("\x89PNG\r\n\x1a\npng")},
117
+
}
118
+
119
+
if _, err := app.installIcon(fsys, "keepassxc.png", "keepassxc"); err != nil {
120
+
t.Fatal(err)
121
+
}
122
+
123
+
if _, err := os.Stat(stale); !os.IsNotExist(err) {
124
+
t.Fatalf("expected stale icon to be removed, stat err: %v", err)
125
+
}
126
+
}
+14
-3
internal/appherder/install.go
+14
-3
internal/appherder/install.go
···
61
61
}
62
62
pin := fingerprint
63
63
64
+
var preparedIcon iconInstall
65
+
iconPath := ""
66
+
if icon != "" {
67
+
prepared, err := a.prepareIconInstall(fsys, icon, appName)
68
+
if err != nil {
69
+
return "", err
70
+
}
71
+
preparedIcon = prepared
72
+
iconPath = preparedIcon.path
73
+
}
74
+
64
75
// No desktop file inside the AppImage: synthesize a terminal launcher so
65
76
// CLI apps still get a menu entry and are tracked by managedApps.
66
77
if desktop == nil {
···
71
82
}
72
83
73
84
// Patch in memory before any filesystem writes so a failure here installs nothing.
74
-
if err := a.patchDesktopFile(desktop, appName, icon != ""); err != nil {
85
+
if err := a.patchDesktopFile(desktop, appName, iconPath); err != nil {
75
86
return "", err
76
87
}
77
88
if pin != "" {
···
86
97
}
87
98
}
88
99
89
-
if icon != "" {
90
-
dest, err := a.installIcon(fsys, icon, appName)
100
+
if iconPath != "" {
101
+
dest, err := a.installPreparedIcon(preparedIcon, appName)
91
102
if err != nil {
92
103
rollback()
93
104
return "", err
+10
internal/appherder/uninstall.go
+10
internal/appherder/uninstall.go
···
25
25
return fmt.Errorf("remove %s: %w", path, err)
26
26
}
27
27
}
28
+
for _, path := range a.installedIconPaths(appName) {
29
+
if err := os.Remove(path); err != nil && !errors.Is(err, os.ErrNotExist) {
30
+
return fmt.Errorf("remove %s: %w", path, err)
31
+
}
32
+
}
28
33
29
34
_ = os.RemoveAll(filepath.Join(a.appimagesDir, ".versions", appName))
30
35
···
39
44
a.linkPath(appName),
40
45
}
41
46
}
47
+
48
+
func (a App) installedIconPaths(appName string) []string {
49
+
matches, _ := filepath.Glob(filepath.Join(a.iconsDir, appName+".*"))
50
+
return matches
51
+
}