ecpg: Catch zero-length Unicode identifiers correctly

petere · petere · commit a18b6d2dc288 · 2022-01-12T10:39:57.000+01:00
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
@@ -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);

Original file line number	Diff line number	Diff line change
`@@ -737,7 +737,7 @@ cppline {space}#([^i][A-Za-z]\|{if}\|{ifdef}\|{ifndef}\|{import})((\/\[^/]\+`
`737`	`737`	`}`
`738`	`738`	`<xui>{dquote} {`
`739`	`739`	`BEGIN(state_before_str_start);`
`740`		`- if (literallen == 2) /* "U&" */`
	`740`	`+ if (literallen == 0)`
`741`	`741`	`mmerror(PARSE_ERROR, ET_ERROR, "zero-length delimited identifier");`
`742`	`742`	`/* The backend will truncate the identifier here. We do not as it does not change the result. */`
`743`	`743`	`base_yylval.str = psprintf("U&\"%s\"", literalbuf);`