Squash all DBRX changes on top of b810fdf. (#673) (#684)

Keep "neon" prefix and visibility.

Also remove idea .gitignore lines, that's a personal developer environment
preference rather than a git repository setup.

Also remove Databricks restrictions.

Author: dimitri

src/backend/access/transam/xlog.c

@@ -5508,7 +5508,8 @@ readNeonSignalFile(void)
 		close(fd);
 
 		elog(LOG,
-			 "[NEON] found 'neon.signal' file. setting prev LSN to %X/%X",
+			 "[NEON] found '%s' file. setting prev LSN to %X/%X",
+			 NEON_SIGNAL_FILE,
 			 LSN_FORMAT_ARGS(neonLastRec));
 	}
 }

src/backend/libpq/auth.c

@@ -229,6 +229,11 @@ static int	PerformRadiusTransaction(const char *server, const char *secret, cons
  */
 ClientAuthentication_hook_type ClientAuthentication_hook = NULL;
 
+/*
+ * This hook calls back Databricks CP for authentication
+ */
+DatabricksAuthentication_hook_type DatabricksAuthentication_hook = NULL;
+
 /*
  * Tell the user the authentication failed, but not (much about) why.
  *
@@ -805,6 +810,15 @@ CheckPasswordAuth(Port *port, const char **logdetail)
 	else
 		result = STATUS_ERROR;
 
+	if (result != STATUS_OK && DatabricksAuthentication_hook)
+	{
+		elog(LOG, "Calling DatabricksAuthentication_hook");
+
+		result = (*DatabricksAuthentication_hook)(port, passwd);
+
+		elog(LOG, "DatabricksAuthentication_hook returned: %d", result);
+	}
+
 	if (shadow_pass)
 		pfree(shadow_pass);
 	pfree(passwd);

src/include/libpq/auth.h

@@ -34,4 +34,8 @@ typedef char *(*auth_password_hook_typ) (char *input);
 /* Default LDAP password mutator hook, can be overridden by a shared library */
 extern PGDLLIMPORT auth_password_hook_typ ldap_password_hook;
 
+/* Hook for databricks authentication */
+typedef int (*DatabricksAuthentication_hook_type) (Port *, char *);
+extern PGDLLIMPORT DatabricksAuthentication_hook_type DatabricksAuthentication_hook;
+
 #endif							/* AUTH_H */