test: require path boundary in cmdline dir matching

Author: cursoragent

lib/instances/manager_test.go

@@ -306,22 +306,75 @@ func killOrphanedProcessesUnderDir(t *testing.T, dataDir string) {
 
 // cmdlineReferencesDir reports whether any argv token is, or lives under, dir.
 func cmdlineReferencesDir(argv []string, dir string) bool {
+	dir = filepath.Clean(dir)
 	for _, tok := range argv {
 		tok = strings.TrimSpace(tok)
 		if tok == "" {
 			continue
 		}
 		// Tokens may embed the path inside larger strings (e.g. qemu's
-		// "socket,...,path=/tmp/.../qmp.sock"), so a substring check on the
-		// cleaned prefix is the robust match. The prefix is a unique per-test
-		// t.TempDir() root, so substring matching cannot collide across tests.
-		if strings.Contains(tok, dir) {
-			return true
+		// "socket,...,path=/tmp/.../qmp.sock"), so scan for occurrences and
+		// require a path boundary at the end of the matched directory.
+		for start := 0; start < len(tok); {
+			idx := strings.Index(tok[start:], dir)
+			if idx < 0 {
+				break
+			}
+			idx += start
+			end := idx + len(dir)
+			if end == len(tok) || (end < len(tok) && os.IsPathSeparator(tok[end])) {
+				return true
+			}
+			start = idx + 1
 		}
 	}
 	return false
 }
 
+func TestCmdlineReferencesDir(t *testing.T) {
+	t.Parallel()
+
+	dir := filepath.Clean(filepath.Join(string(os.PathSeparator), "tmp", "hypeman", "001"))
+
+	tests := []struct {
+		name string
+		argv []string
+		want bool
+	}{
+		{
+			name: "exact token",
+			argv: []string{"qemu-system-x86_64", dir},
+			want: true,
+		},
+		{
+			name: "embedded under dir",
+			argv: []string{
+				"cloud-hypervisor",
+				"--api-sock",
+				"socket,id=qmp,path=" + filepath.Join(dir, "instances", "vm-1", "qmp.sock"),
+			},
+			want: true,
+		},
+		{
+			name: "sibling dir with prefix is not a match",
+			argv: []string{
+				"cloud-hypervisor",
+				"--api-sock",
+				"socket,id=qmp,path=" + filepath.Join(string(os.PathSeparator), "tmp", "hypeman", "0010", "instances", "vm-1", "qmp.sock"),
+			},
+			want: false,
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			assert.Equal(t, tt.want, cmdlineReferencesDir(tt.argv, dir))
+		})
+	}
+}
+
 func isGuestProcess(exe string) bool {
 	switch {
 	case exe == "firecracker":