postgresql: rename patches

Trying to understand what each patch does made me come up with some more
descriptive names:

- Renaming the two disable-xxx patches to a common names makes it immediately
  clear that one replaces the other depending on version number.
- findstring was really not descriptive at all.
- hardcode-pgxs-path will be extended with more paths for split outputs in
  a later commit. Renaming here already to allow git to better track renames.

Finally replacing HARDCODED_PGXS_PATH with $out/lib in the last patch, makes
it easier to understand what the end result will look like when reading the
patch.

pkgs/servers/sql/postgresql/generic.nix

@@ -111,12 +111,11 @@ let
       ++ lib.optionals stdenv'.isLinux [ "--with-pam" ];
 
     patches = [
-      (if atLeast "16" then ./patches/disable-normalize_exec_path.patch
-       else ./patches/disable-resolve_symlinks.patch)
+      (if atLeast "16" then ./patches/relative-to-symlinks-16+.patch else ./patches/relative-to-symlinks.patch)
       ./patches/less-is-more.patch
-      ./patches/hardcode-pgxs-path.patch
+      ./patches/paths-for-split-outputs.patch
       ./patches/specify_pkglibdir_at_runtime.patch
-      ./patches/findstring.patch
+      ./patches/paths-with-postgresql-suffix.patch
 
       (substituteAll {
         src = ./patches/locale-binary-path.patch;
@@ -127,7 +126,7 @@ let
       # Using fetchurl instead of fetchpatch on purpose: https://github.com/NixOS/nixpkgs/issues/240141
       map fetchurl (lib.attrValues muslPatches)
     ) ++ lib.optionals stdenv'.isLinux  [
-      (if atLeast "13" then ./patches/socketdir-in-run-13.patch else ./patches/socketdir-in-run.patch)
+      (if atLeast "13" then ./patches/socketdir-in-run-13+.patch else ./patches/socketdir-in-run.patch)
     ];
 
     installTargets = [ "install-world" ];
@@ -136,7 +135,7 @@ let
 
     postPatch = ''
       # Hardcode the path to pgxs so pg_config returns the path in $out
-      substituteInPlace "src/common/config_info.c" --replace HARDCODED_PGXS_PATH "$out/lib"
+      substituteInPlace "src/common/config_info.c" --subst-var out
     '' + lib.optionalString jitSupport ''
         # Force lookup of jit stuff in $out instead of $lib
         substituteInPlace src/backend/jit/jit.c --replace pkglib_path \"$out/lib\"

pkgs/servers/sql/postgresql/patches/paths-for-split-outputs.patch

@@ -1,13 +1,11 @@
 --- a/src/common/config_info.c
 +++ b/src/common/config_info.c
-@@ -118,7 +118,10 @@
+@@ -118,7 +118,7 @@
  	i++;
 
  	configdata[i].name = pstrdup("PGXS");
-+	strlcpy(path, "HARDCODED_PGXS_PATH", sizeof(path));
-+/* commented out to be able to point to nix $out path
- 	get_pkglib_path(my_exec_path, path);
-+*/
++	strlcpy(path, "@out@/lib", sizeof(path));
+-	get_pkglib_path(my_exec_path, path);
  	strlcat(path, "/pgxs/src/makefiles/pgxs.mk", sizeof(path));
  	cleanup_path(path);
  	configdata[i].setting = pstrdup(path);

pkgs/servers/sql/postgresql/patches/paths-with-postgresql-suffix.patch

@@ -1,7 +1,3 @@
-From: Matthew Bauer <mjbauer95@gmail.com>
-Date: Wed, 29 May 2019 22:51:52 -0400
-Subject: [PATCH] Add /postgresql suffix for Nix outputs
-
 Nix outputs put the `name' in each store path like
 /nix/store/...-<name>. This was confusing the Postgres make script
 because it thought its data directory already had postgresql in its

pkgs/servers/sql/postgresql/patches/relative-to-symlinks-16+.patch

@@ -1,10 +1,11 @@
+On NixOS we *want* stuff relative to symlinks.
+---
 --- a/src/common/exec.c
 +++ b/src/common/exec.c
-@@ -238,6 +238,9 @@
+@@ -238,6 +238,8 @@
  static int
  normalize_exec_path(char *path)
  {
-+	// On NixOS we *want* stuff relative to symlinks.
 +	return 0;
 +
  	/*

pkgs/servers/sql/postgresql/patches/relative-to-symlinks.patch

@@ -1,10 +1,11 @@
+On NixOS we *want* stuff relative to symlinks.
+---
 --- a/src/common/exec.c
 +++ b/src/common/exec.c
-@@ -218,6 +218,9 @@
+@@ -218,6 +218,8 @@
  static int
  resolve_symlinks(char *path)
  {
-+	// On NixOS we *want* stuff relative to symlinks.
 +	return 0;
 +
  #ifdef HAVE_READLINK