From: Peter Eisentraut <peter@eisentraut.org>
Date: Wed, 12 Jan 2022 09:39:57 +0000 (+0100)
Subject: ecpg: Catch zero-length Unicode identifiers correctly
X-Git-Tag: REL_15_BETA1~929
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a18b6d2dc288dfa6e7905ede1d4462edd6a8af47;p=thirdparty%2Fpostgresql.git

ecpg: Catch zero-length Unicode identifiers correctly

The previous code to detect a zero-length identifier when using
Unicode identifiers such as

exec sql select u&"";

did not work.  This fixes that.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/82fafa79-331c-9d65-e51b-8b5d1b2383fc%40enterprisedb.com
---

diff --git a/src/interfaces/ecpg/preproc/pgc.l b/src/interfaces/ecpg/preproc/pgc.l
index 39e578e8685..9286a0355d6 100644
--- a/src/interfaces/ecpg/preproc/pgc.l
+++ b/src/interfaces/ecpg/preproc/pgc.l
@@ -737,7 +737,7 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifndef}|{import})((\/\*[^*/]*\*+
 				}
 <xui>{dquote}	{
 					BEGIN(state_before_str_start);
-					if (literallen == 2) /* "U&" */
+					if (literallen == 0)
 						mmerror(PARSE_ERROR, ET_ERROR, "zero-length delimited identifier");
 					/* The backend will truncate the identifier here. We do not as it does not change the result. */
 					base_yylval.str = psprintf("U&\"%s\"", literalbuf);