From: Peter Eisentraut <peter@eisentraut.org>
Date: Wed, 15 May 2024 11:49:41 +0000 (+0200)
Subject: Re-forbid underscore in positional parameters
X-Git-Tag: REL_17_BETA1~34
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=98b4f53d15;p=postgresql.git

Re-forbid underscore in positional parameters

Underscores were added to numeric literals in faff8f8e47.  This change
also affected the positional parameters (e.g., $1) rule, which uses
the same production for its digits.  But this did not actually work,
because the digits for parameters are processed using atol(), which
does not handle underscores and ignores whatever it cannot parse.

The underscores notation is probably not useful for positional
parameters, so for simplicity revert that rule to its old form that
only accepts digits 0-9.

Author: Erik Wienhold <ewie@ewie.name>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/5d216d1c-91f6-4cbe-95e2-b4cbd930520c%40ewie.name
---

diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l
index 5eaadf53b20..b499975e9c4 100644
--- a/src/backend/parser/scan.l
+++ b/src/backend/parser/scan.l
@@ -419,8 +419,9 @@ bininteger_junk	{bininteger}{ident_start}
 numeric_junk	{numeric}{ident_start}
 real_junk		{real}{ident_start}
 
-param			\${decinteger}
-param_junk		\${decinteger}{ident_start}
+/* Positional parameters don't accept underscores. */
+param			\${decdigit}+
+param_junk		\${decdigit}+{ident_start}
 
 other			.
 
diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l
index c9df0594fda..c6d02439ab2 100644
--- a/src/fe_utils/psqlscan.l
+++ b/src/fe_utils/psqlscan.l
@@ -355,8 +355,9 @@ bininteger_junk	{bininteger}{ident_start}
 numeric_junk	{numeric}{ident_start}
 real_junk		{real}{ident_start}
 
-param			\${decinteger}
-param_junk		\${decinteger}{ident_start}
+/* Positional parameters don't accept underscores. */
+param			\${decdigit}+
+param_junk		\${decdigit}+{ident_start}
 
 /* psql-specific: characters allowed in variable names */
 variable_char	[A-Za-z\200-\377_0-9]
diff --git a/src/interfaces/ecpg/preproc/pgc.l b/src/interfaces/ecpg/preproc/pgc.l
index bcfbd0978bb..d117cafce65 100644
--- a/src/interfaces/ecpg/preproc/pgc.l
+++ b/src/interfaces/ecpg/preproc/pgc.l
@@ -388,8 +388,9 @@ bininteger_junk	{bininteger}{ident_start}
 numeric_junk	{numeric}{ident_start}
 real_junk		{real}{ident_start}
 
-param			\${decinteger}
-param_junk		\${decinteger}{ident_start}
+/* Positional parameters don't accept underscores. */
+param			\${decdigit}+
+param_junk		\${decdigit}+{ident_start}
 
 /* special characters for other dbms */
 /* we have to react differently in compat mode */
diff --git a/src/test/regress/expected/numerology.out b/src/test/regress/expected/numerology.out
index f662a5050ac..c8196d2c85a 100644
--- a/src/test/regress/expected/numerology.out
+++ b/src/test/regress/expected/numerology.out
@@ -330,6 +330,10 @@ SELECT 1_000.5e_1;
 ERROR:  trailing junk after numeric literal at or near "1_000.5e"
 LINE 1: SELECT 1_000.5e_1;
                ^
+PREPARE p1 AS SELECT $0_1;
+ERROR:  trailing junk after parameter at or near "$0_"
+LINE 1: PREPARE p1 AS SELECT $0_1;
+                             ^
 --
 -- Test implicit type conversions
 -- This fails for Postgres v6.1 (and earlier?)
diff --git a/src/test/regress/sql/numerology.sql b/src/test/regress/sql/numerology.sql
index 1941c58e681..3f0ec34ecfa 100644
--- a/src/test/regress/sql/numerology.sql
+++ b/src/test/regress/sql/numerology.sql
@@ -88,6 +88,7 @@ SELECT 1_000._5;
 SELECT 1_000.5_;
 SELECT 1_000.5e_1;
 
+PREPARE p1 AS SELECT $0_1;
 
 --
 -- Test implicit type conversions