diff --git a/src/backend/utils/misc/guc-file.l b/src/backend/utils/misc/guc-file.l
index 1c8b5f7..125b898 100644
--- a/src/backend/utils/misc/guc-file.l
+++ b/src/backend/utils/misc/guc-file.l
@@ -568,6 +568,22 @@ ParseConfigFile(const char *config_file, bool strict,
 	FILE	   *fp;
 
 	/*
+	 * Reject file name that is all-blank (including empty), as that leads to
+	 * confusion, or even recursive inclusion in some cases.
+	 */
+	if (strspn(config_file, " \t\r\n") == strlen(config_file))
+	{
+		ereport(elevel,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("empty configuration file name: \"%s\"",
+						config_file)));
+		record_config_file_error("empty configuration file name",
+								 calling_file, calling_lineno,
+								 head_p, tail_p);
+		return false;
+	}
+
+	/*
 	 * Reject too-deep include nesting depth.  This is just a safety check to
 	 * avoid dumping core due to stack overflow if an include file loops back
 	 * to itself.  The maximum nesting depth is pretty arbitrary.
@@ -585,6 +601,26 @@ ParseConfigFile(const char *config_file, bool strict,
 	}
 
 	abs_path = AbsoluteConfigLocation(config_file, calling_file);
+
+	/*
+	 * Reject direct recursion.  Indirect recursion is also possible, but it's
+	 * harder to detect and so doesn't seem worth the trouble.  (We test at
+	 * this step because the canonicalization done by AbsoluteConfigLocation
+	 * makes it more likely that a simple strcmp comparison will match.)
+	 */
+	if (calling_file && strcmp(abs_path, calling_file) == 0)
+	{
+		ereport(elevel,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("configuration file recursion in \"%s\"",
+						calling_file)));
+		record_config_file_error("configuration file recursion",
+								 calling_file, calling_lineno,
+								 head_p, tail_p);
+		pfree(abs_path);
+		return false;
+	}
+
 	fp = AllocateFile(abs_path, "r");
 	if (!fp)
 	{
@@ -933,6 +969,27 @@ ParseConfigDirectory(const char *includedir,
 	int			size_filenames;
 	bool		status;
 
+	/*
+	 * Reject directory name that is all-blank (including empty), as that
+	 * leads to confusion, or even recursive inclusion in some cases.
+	 */
+	if (strspn(includedir, " \t\r\n") == strlen(includedir))
+	{
+		ereport(elevel,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("empty configuration directory name: \"%s\"",
+						includedir)));
+		record_config_file_error("empty configuration directory name",
+								 calling_file, calling_lineno,
+								 head_p, tail_p);
+		return false;
+	}
+
+	/*
+	 * We don't check for recursion or too-deep nesting depth here; the
+	 * subsequent calls to ParseConfigFile will take care of that.
+	 */
+
 	directory = AbsoluteConfigLocation(includedir, calling_file);
 	d = AllocateDir(directory);
 	if (d == NULL)