From a8ae12322ae056ebbe9d83cf16b4c92e86a6ac28 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 21 Dec 2016 17:39:32 -0500
Subject: [PATCH] Fix detection of unfinished Unicode surrogate pair at end of
string.
The U&'...' and U&"..." syntaxes silently discarded a surrogate pair
start (that is, a code between U+D800 and U+DBFF) if it occurred at
the very end of the string. This seems like an obvious oversight,
since we throw an error for every other invalid combination of surrogate
characters, including the very same situation in E'...' syntax.
This has been wrong since the pair processing was added (in 9.0),
so back-patch to all supported branches.
Discussion: https://postgr.es/m/19113.1482337898@sss.pgh.pa.us
---
src/backend/parser/scan.l | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l
index 998349d7421..acd92698057 100644
--- a/src/backend/parser/scan.l
+++ b/src/backend/parser/scan.l
@@ -1435,6 +1435,13 @@ litbuf_udeescape(unsigned char escape, core_yyscan_t yyscanner)
}
}
+ /* unfinished surrogate pair? */
+ if (pair_first)
+ {
+ ADVANCE_YYLLOC(in - litbuf + 3); /* 3 for U&" */
+ yyerror("invalid Unicode surrogate pair");
+ }
+
*out = '\0';
/*
--
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