postgresql_13: init at 13.0

https://www.postgresql.org/docs/13/release-13.html

pkgs/servers/sql/postgresql/default.nix

···
         (if atLeast "9.6" then ./patches/hardcode-pgxs-path-96.patch       else ./patches/hardcode-pgxs-path.patch)
         ./patches/specify_pkglibdir_at_runtime.patch
         ./patches/findstring.patch
-      ] ++ lib.optional stdenv.isLinux ./patches/socketdir-in-run.patch;
+      ] ++ lib.optional stdenv.isLinux (if atLeast "13" then ./patches/socketdir-in-run-13.patch else ./patches/socketdir-in-run.patch);
 
     installTargets = [ "install-world" ];
 
···
     psqlSchema = "12";
     sha256 = "1k06wryy8p4s1fim9qafcjlak3f58l0wqaqnrccr9x9j5jz3zsdy";
     this = self.postgresql_12;
+    inherit self;
+  };
+
+  postgresql_13 = self.callPackage generic {
+    version = "13.0";
+    psqlSchema = "13";
+    sha256 = "15i2b7m9a9430idqdgvrcyx66cpxz0v2d81nfqcm8ss3inz51rw0";
+    this = self.postgresql_13;
     inherit self;
   };
 

pkgs/servers/sql/postgresql/patches/socketdir-in-run-13.patch

···
+diff --git i/src/include/pg_config_manual.h w/src/include/pg_config_manual.h
+index 8f3ec6bde1..4fc01e4a0a 100644
+--- i/src/include/pg_config_manual.h
++++ w/src/include/pg_config_manual.h
+@@ -201,7 +201,7 @@
+  * support them yet.
+  */
+ #ifndef WIN32
+-#define DEFAULT_PGSOCKET_DIR  "/tmp"
++#define DEFAULT_PGSOCKET_DIR  "/run/postgresql"
+ #else
+ #define DEFAULT_PGSOCKET_DIR ""
+ #endif

pkgs/top-level/all-packages.nix

···
     postgresql_10
     postgresql_11
     postgresql_12
+    postgresql_13
   ;
   postgresql = postgresql_11.override { this = postgresql; };
   postgresqlPackages = recurseIntoAttrs postgresql.pkgs;