Fix squashing algorithm for query texts

The algorithm to squash lists of constants added by commit 62d712ecfd94
was a bit too simplistic; we wanted to avoid adding unnecessary
complexity, but cases like direct function calls of typecasting
functions (and others) were missed, and bogus SQL syntax was being shown
in pg_stat_statements normalized query text field.  To fix normalization
for those cases, we need the parser to transmit information about were
each list of constant values starts and ends, so add that to a couple of
nodes.  Also add a few more test cases to make sure we're doing the
right thing.

The patch initially submitted by Sami added a new private struct in
gram.y to carry the start/end information for A_Expr, but I (Álvaro)
decided that a better fix was to remove the parser indirection via the
in_expr production, and instead create separate components in the a_expr
rule.  I'm surprised that this works and doesn't require more changes,
but I assume (without checking) that the grammar used to be more complex
and got simplified at some point.

Bump catversion.

Author: Sami Imseih <samimseih@gmail.com>
Author: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAA5RZ0tRXoPG2y6bMgBCWNDt0Tn=unRerbzYM=oW0syi1=C1OA@mail.gmail.com

3 files changed, 15 insertions, 1 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index f2971485d8f..67fbe9c9292 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202506021
+#define CATALOG_VERSION_NO	202506121
 
 #endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0c1120beff3..ba12678d1cb 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -351,6 +351,14 @@ typedef struct A_Expr
 	List	   *name;			/* possibly-qualified name of operator */
 	Node	   *lexpr;			/* left argument, or NULL if none */
 	Node	   *rexpr;			/* right argument, or NULL if none */
+
+	/*
+	 * If rexpr is a list of some kind, we separately track its starting and
+	 * ending location; it's not the same as the starting and ending location
+	 * of the token itself.
+	 */
+	ParseLoc	rexpr_list_start;
+	ParseLoc	rexpr_list_end;
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } A_Expr;
 
@@ -506,6 +514,8 @@ typedef struct A_ArrayExpr
 {
 	NodeTag		type;
 	List	   *elements;		/* array element expressions */
+	ParseLoc	list_start;		/* start of the element list */
+	ParseLoc	list_end;		/* end of the elements list */
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } A_ArrayExpr;
 
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 7d3b4198f26..01510b01b64 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1397,6 +1397,10 @@ typedef struct ArrayExpr
 	List	   *elements pg_node_attr(query_jumble_squash);
 	/* true if elements are sub-arrays */
 	bool		multidims pg_node_attr(query_jumble_ignore);
+	/* location of the start of the elements list */
+	ParseLoc	list_start;
+	/* location of the end of the elements list */
+	ParseLoc	list_end;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } ArrayExpr;