fix: mounting issue with single character volume on windows

fixes https://github.com/containers/podman/issues/25218

Signed-off-by: axel7083 <42176370+axel7083@users.noreply.github.com>

pkg/machine/e2e/basic_test.go

@@ -102,6 +102,32 @@ var _ = Describe("run basic podman commands", func() {
 		Expect(build).To(Exit(0))
 	})
 
+	It("Single character volume mount", func() {
+		// Get a tmp directory
+		tDir, err := filepath.Abs(GinkgoT().TempDir())
+		Expect(err).ToNot(HaveOccurred())
+		name := randomString()
+		i := new(initMachine).withImage(mb.imagePath).withNow()
+
+		// All other platforms have an implicit mount for the temp area
+		if isVmtype(define.QemuVirt) {
+			i.withVolume(tDir)
+		}
+		session, err := mb.setName(name).setCmd(i).run()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(session).To(Exit(0))
+
+		bm := basicMachine{}
+
+		volumeCreate, err := mb.setCmd(bm.withPodmanCommand([]string{"volume", "create", "a"})).run()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(volumeCreate).To(Exit(0))
+
+		run, err := mb.setCmd(bm.withPodmanCommand([]string{"run", "-v", "a:/test:Z", "quay.io/libpod/alpine_nginx", "true"})).run()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(run).To(Exit(0))
+	})
+
 	It("Volume should be virtiofs", func() {
 		// In theory this could run on MacOS too, but we know virtiofs works for that now,
 		// this is just testing linux

pkg/specgen/volumes.go

@@ -225,8 +225,9 @@ func GenVolumeMounts(volumeFlag []string) (map[string]spec.Mount, map[string]*Na
 	return mounts, volumes, overlayVolumes, nil
 }
 
-// Splits a volume string, accounting for Win drive paths
+// SplitVolumeString Splits a volume string, accounting for Win drive paths
 // when running as a WSL linux guest or Windows client
+// Format: [[SOURCE-VOLUME|HOST-DIR:]CONTAINER-DIR[:OPTIONS]]
 func SplitVolumeString(vol string) []string {
 	parts := strings.Split(vol, ":")
 	if !shouldResolveWinPaths() {
@@ -239,6 +240,20 @@ func SplitVolumeString(vol string) []string {
 		n = 4
 	}
 
+	// Determine if the last part is an absolute path (if true, it means we don't have any options such as ro, rw etc.)
+	lastPartIsPath := strings.HasPrefix(parts[len(parts)-1], "/")
+
+	// Case: Volume or relative host path (e.g., "vol-name:/container" or "./hello:/container")
+	if lastPartIsPath && len(parts) == 2 {
+		return parts
+	}
+
+	// Case: Volume or relative host path with options (e.g., "vol-name:/container:ro" or "./hello:/container:ro")
+	if !lastPartIsPath && len(parts) == 3 {
+		return parts
+	}
+
+	// Case: Windows absolute path (e.g., "C:/Users:/mnt:ro")
 	if hasWinDriveScheme(vol, n) {
 		first := parts[0] + ":" + parts[1]
 		parts = parts[1:]

pkg/specgen/volumes_linux_test.go

@@ -0,0 +1,72 @@
+package specgen
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSplitVolumeString(t *testing.T) {
+	tests := []struct {
+		name   string
+		volume string
+		expect []string
+	}{
+		// relative host paths
+		{
+			name:   "relative host path",
+			volume: "./hello:/container",
+			expect: []string{"./hello", "/container"},
+		},
+		{
+			name:   "relative host path with options",
+			volume: "./hello:/container:ro",
+			expect: []string{"./hello", "/container", "ro"},
+		},
+		// absolute host path
+		{
+			name:   "absolute host path",
+			volume: "/hello:/container",
+			expect: []string{"/hello", "/container"},
+		},
+		{
+			name:   "absolute host path with option",
+			volume: "/hello:/container:ro",
+			expect: []string{"/hello", "/container", "ro"},
+		},
+		{
+			name:   "absolute host path with option",
+			volume: "/hello:/container:ro",
+			expect: []string{"/hello", "/container", "ro"},
+		},
+		// volume source
+		{
+			name:   "volume without option",
+			volume: "vol-name:/container",
+			expect: []string{"vol-name", "/container"},
+		},
+		{
+			name:   "volume with option",
+			volume: "vol-name:/container:ro",
+			expect: []string{"vol-name", "/container", "ro"},
+		},
+		{
+			name:   "single letter volume without option",
+			volume: "a:/container",
+			expect: []string{"a", "/container"},
+		},
+		{
+			name:   "single letter volume with option",
+			volume: "a:/container:ro",
+			expect: []string{"a", "/container", "ro"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			parts := SplitVolumeString(tt.volume)
+
+			assert.Equal(t, tt.expect, parts, tt.name)
+		})
+	}
+}

pkg/specgen/volumes_windows_test.go

@@ -0,0 +1,77 @@
+package specgen
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSplitVolumeString(t *testing.T) {
+	tests := []struct {
+		name   string
+		volume string
+		expect []string
+	}{
+		// relative host paths
+		{
+			name:   "relative host path",
+			volume: "./hello:/container",
+			expect: []string{"./hello", "/container"},
+		},
+		{
+			name:   "relative host path with options",
+			volume: "./hello:/container:ro",
+			expect: []string{"./hello", "/container", "ro"},
+		},
+		// absolute host path
+		{
+			name:   "absolute host path",
+			volume: "C:\\hello:/container",
+			expect: []string{"C:\\hello", "/container"},
+		},
+		{
+			name:   "absolute host path with option",
+			volume: "C:\\hello:/container:ro",
+			expect: []string{"C:\\hello", "/container", "ro"},
+		},
+		{
+			name:   "absolute host path with option",
+			volume: "C:\\hello:/container:ro",
+			expect: []string{"C:\\hello", "/container", "ro"},
+		},
+		{
+			name:   "absolute extended host path",
+			volume: `\\?\C:\hello:/container`,
+			expect: []string{`\\?\C:\hello`, "/container"},
+		},
+		// volume source
+		{
+			name:   "volume without option",
+			volume: "vol-name:/container",
+			expect: []string{"vol-name", "/container"},
+		},
+		{
+			name:   "volume with option",
+			volume: "vol-name:/container:ro",
+			expect: []string{"vol-name", "/container", "ro"},
+		},
+		{
+			name:   "single letter volume without option",
+			volume: "a:/container",
+			expect: []string{"a", "/container"},
+		},
+		{
+			name:   "single letter volume with option",
+			volume: "a:/container:ro",
+			expect: []string{"a", "/container", "ro"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			parts := SplitVolumeString(tt.volume)
+
+			assert.Equal(t, tt.expect, parts, tt.name)
+		})
+	}
+}

test/e2e/run_volume_test.go

@@ -145,6 +145,19 @@ var _ = Describe("Podman run with volumes", func() {
 		Expect(session).To(ExitWithError(125, fmt.Sprintf("%s: duplicate mount destination", dest)))
 	})
 
+	It("podman run with single character volume", func() {
+		// 1. create single character volume
+		session := podmanTest.Podman([]string{"volume", "create", "a"})
+		session.WaitWithDefaultTimeout()
+		volName := session.OutputToString()
+		Expect(session).Should(ExitCleanly())
+
+		// 2. create container with volume
+		session = podmanTest.Podman([]string{"run", "--volume", volName + ":/data", ALPINE, "sh", "-c", "echo hello world"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(ExitCleanly())
+	})
+
 	It("podman run with conflict between image volume and user mount succeeds", func() {
 		err = podmanTest.RestoreArtifact(REDIS_IMAGE)
 		Expect(err).ToNot(HaveOccurred())