libpq@15: add libpq 15.8

Aliases/libpq@17

@@ -0,0 +1 @@
+../Formula/lib/libpq.rb

Formula/lib/libpq@15.rb

@@ -0,0 +1,79 @@
+class LibpqAT15 < Formula
+  desc "Postgres C API library"
+  homepage "https://www.postgresql.org/docs/15/libpq.html"
+  url "https://ftp.postgresql.org/pub/source/v15.8/postgresql-15.8.tar.bz2"
+  sha256 "4403515f9a69eeb3efebc98f30b8c696122bfdf895e92b3b23f5b8e769edcb6a"
+  license "PostgreSQL"
+
+  livecheck do
+    url "https://ftp.postgresql.org/pub/source/"
+    regex(%r{href=["']?v?(\d+(?:\.\d+)+)/?["' >]}i)
+  end
+
+  keg_only "conflicts with postgres formula"
+  keg_only :versioned_formula
+
+  # GSSAPI provided by Kerberos.framework crashes when forked.
+  # See https://github.com/Homebrew/homebrew-core/issues/47494.
+  depends_on "krb5"
+
+  depends_on "openssl@3"
+
+  uses_from_macos "zlib"
+
+  on_linux do
+    depends_on "readline"
+  end
+
+  def install
+    system "./configure", "--disable-debug",
+                          "--prefix=#{prefix}",
+                          "--with-gssapi",
+                          "--with-openssl",
+                          "--libdir=#{opt_lib}",
+                          "--includedir=#{opt_include}"
+    dirs = %W[
+      libdir=#{lib}
+      includedir=#{include}
+      pkgincludedir=#{include}/postgresql
+      includedir_server=#{include}/postgresql/server
+      includedir_internal=#{include}/postgresql/internal
+    ]
+    system "make"
+    system "make", "-C", "src/bin", "install", *dirs
+    system "make", "-C", "src/include", "install", *dirs
+    system "make", "-C", "src/interfaces", "install", *dirs
+    system "make", "-C", "src/common", "install", *dirs
+    system "make", "-C", "src/port", "install", *dirs
+    system "make", "-C", "doc", "install", *dirs
+  end
+
+  test do
+    (testpath/"libpq.c").write <<~EOS
+      #include <stdlib.h>
+      #include <stdio.h>
+      #include <libpq-fe.h>
+
+      int main()
+      {
+          const char *conninfo;
+          PGconn     *conn;
+
+          conninfo = "dbname = postgres";
+
+          conn = PQconnectdb(conninfo);
+
+          if (PQstatus(conn) != CONNECTION_OK) // This should always fail
+          {
+              printf("Connection to database attempted and failed");
+              PQfinish(conn);
+              exit(0);
+          }
+
+          return 0;
+        }
+    EOS
+    system ENV.cc, "libpq.c", "-L#{lib}", "-I#{include}", "-lpq", "-o", "libpqtest"
+    assert_equal "Connection to database attempted and failed", shell_output("./libpqtest")
+  end
+end