Update the xiaq/persistent dependency.

NEXT-RELEASE.md

@@ -44,3 +44,7 @@ New features in the standard library:
 
 -   A new `eval` command supports evaluating a dynamic piece of code in a
     restricted namespace.
+
+# Notable bugfixes
+
+-   Using large lists that contain `$nil` no longer crashes Elvish.

go.mod

@@ -4,7 +4,7 @@ require (
 	github.com/BurntSushi/toml v0.3.1
 	github.com/kr/pty v1.1.4
 	github.com/mattn/go-isatty v0.0.12
-	github.com/xiaq/persistent v0.0.0-20200713233553-14b5bdc771d3
+	github.com/xiaq/persistent v0.0.0-20200820214153-3175cfb92e14
 	go.etcd.io/bbolt v1.3.4
 	golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd
 )

go.sum

@@ -2,15 +2,12 @@ github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/kr/pty v1.1.4 h1:5Myjjh3JY/NaAi4IsUbHADytDyl1VE1Y9PXDlL+P/VQ=
 github.com/kr/pty v1.1.4/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/mattn/go-isatty v0.0.11 h1:FxPOTFNqGkuDUGi3H/qkUbQO4ZiBa2brKq5r0l8TGeM=
-github.com/mattn/go-isatty v0.0.11/go.mod h1:PhnuNfih5lzO57/f3n+odYbM4JtupLOxQOAqxQCu2WE=
 github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
-github.com/xiaq/persistent v0.0.0-20200713233553-14b5bdc771d3 h1:A89V6pky+I7R7he7WBNFC7A8fNTmf8CllT6fDc7pVRU=
-github.com/xiaq/persistent v0.0.0-20200713233553-14b5bdc771d3/go.mod h1:ezTJjR1ZWIJvN9QAd79tCd/TO4X3x7FDbLMEGHOI1LA=
+github.com/xiaq/persistent v0.0.0-20200820214153-3175cfb92e14 h1:HxX+USVm4XyGwvWS0eJy+GMttkfSRdFcrZ46WtAs5RQ=
+github.com/xiaq/persistent v0.0.0-20200820214153-3175cfb92e14/go.mod h1:ezTJjR1ZWIJvN9QAd79tCd/TO4X3x7FDbLMEGHOI1LA=
 go.etcd.io/bbolt v1.3.4 h1:hi1bXHMVrlQh6WwxAy+qZCV/SYIlqo+Ushwdpa4tAKg=
 go.etcd.io/bbolt v1.3.4/go.mod h1:G5EMThwa9y8QZGBClrRx5EY+Yw9kAhnjy3bSjsnlVTQ=
-golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5 h1:LfCXLvNmTYH9kEmVgqbnsWfruoXZIrh4YBgqVHtDvw0=
 golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=