Be more careful with error paths in pg_set_regex_collation().

jeff-davis · jeff-davis · commit 7829f85a6285 · 2024-09-05T12:10:08.000-07:00
Set global variables after error paths so that they don't end up in an inconsistent state. The inconsistent state doesn't lead to an actual problem, because after an error, pg_set_regex_collation() will be called again before the globals are accessed. Change extracted from patch by Andreas Karlsson, though not discussed explicitly. Discussion: https://postgr.es/m/60929555-4709-40a7-b136-bcb44cff5a3c@proxel.se
diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
@@ -231,6 +231,9 @@ static const unsigned char pg_char_properties[128] = {
 void
 pg_set_regex_collation(Oid collation)
 {
+	pg_locale_t locale = 0;
+	PG_Locale_Strategy strategy;
+
 	if (!OidIsValid(collation))
 	{
 		/*
@@ -246,40 +249,41 @@ pg_set_regex_collation(Oid collation)
 	if (lc_ctype_is_c(collation))
 	{
 		/* C/POSIX collations use this path regardless of database encoding */
-		pg_regex_strategy = PG_REGEX_STRATEGY_C;
-		pg_regex_locale = 0;
-		pg_regex_collation = C_COLLATION_OID;
+		strategy = PG_REGEX_STRATEGY_C;
+		collation = C_COLLATION_OID;
 	}
 	else
 	{
-		pg_regex_locale = pg_newlocale_from_collation(collation);
+		locale = pg_newlocale_from_collation(collation);
 
-		if (!pg_locale_deterministic(pg_regex_locale))
+		if (!pg_locale_deterministic(locale))
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("nondeterministic collations are not supported for regular expressions")));
 
-		if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		if (locale->provider == COLLPROVIDER_BUILTIN)
 		{
 			Assert(GetDatabaseEncoding() == PG_UTF8);
-			pg_regex_strategy = PG_REGEX_STRATEGY_BUILTIN;
+			strategy = PG_REGEX_STRATEGY_BUILTIN;
 		}
 #ifdef USE_ICU
-		else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		else if (locale->provider == COLLPROVIDER_ICU)
 		{
-			pg_regex_strategy = PG_REGEX_STRATEGY_ICU;
+			strategy = PG_REGEX_STRATEGY_ICU;
 		}
 #endif
 		else
 		{
 			if (GetDatabaseEncoding() == PG_UTF8)
-				pg_regex_strategy = PG_REGEX_STRATEGY_LIBC_WIDE;
+				strategy = PG_REGEX_STRATEGY_LIBC_WIDE;
 			else
-				pg_regex_strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;
+				strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;
 		}
-
-		pg_regex_collation = collation;
 	}
+
+	pg_regex_strategy = strategy;
+	pg_regex_locale = locale;
+	pg_regex_collation = collation;
 }
 
 static int

Original file line number	Diff line number	Diff line change
`@@ -231,6 +231,9 @@ static const unsigned char pg_char_properties[128] = {`
`231`	`231`	`void`
`232`	`232`	`pg_set_regex_collation(Oid collation)`
`233`	`233`	`{`
	`234`	`+ pg_locale_t locale = 0;`
	`235`	`+ PG_Locale_Strategy strategy;`
	`236`	`+`
`234`	`237`	`if (!OidIsValid(collation))`
`235`	`238`	`{`
`236`	`239`	`/*`
`@@ -246,40 +249,41 @@ pg_set_regex_collation(Oid collation)`
`246`	`249`	`if (lc_ctype_is_c(collation))`
`247`	`250`	`{`
`248`	`251`	`/* C/POSIX collations use this path regardless of database encoding */`
`249`		`- pg_regex_strategy = PG_REGEX_STRATEGY_C;`
`250`		`- pg_regex_locale = 0;`
`251`		`- pg_regex_collation = C_COLLATION_OID;`
	`252`	`+ strategy = PG_REGEX_STRATEGY_C;`
	`253`	`+ collation = C_COLLATION_OID;`
`252`	`254`	`}`
`253`	`255`	`else`
`254`	`256`	`{`
`255`		`- pg_regex_locale = pg_newlocale_from_collation(collation);`
	`257`	`+ locale = pg_newlocale_from_collation(collation);`
`256`	`258`
`257`		`- if (!pg_locale_deterministic(pg_regex_locale))`
	`259`	`+ if (!pg_locale_deterministic(locale))`
`258`	`260`	`ereport(ERROR,`
`259`	`261`	`(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),`
`260`	`262`	`errmsg("nondeterministic collations are not supported for regular expressions")));`
`261`	`263`
`262`		`- if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)`
	`264`	`+ if (locale->provider == COLLPROVIDER_BUILTIN)`
`263`	`265`	`{`
`264`	`266`	`Assert(GetDatabaseEncoding() == PG_UTF8);`
`265`		`- pg_regex_strategy = PG_REGEX_STRATEGY_BUILTIN;`
	`267`	`+ strategy = PG_REGEX_STRATEGY_BUILTIN;`
`266`	`268`	`}`
`267`	`269`	`#ifdef USE_ICU`
`268`		`- else if (pg_regex_locale->provider == COLLPROVIDER_ICU)`
	`270`	`+ else if (locale->provider == COLLPROVIDER_ICU)`
`269`	`271`	`{`
`270`		`- pg_regex_strategy = PG_REGEX_STRATEGY_ICU;`
	`272`	`+ strategy = PG_REGEX_STRATEGY_ICU;`
`271`	`273`	`}`
`272`	`274`	`#endif`
`273`	`275`	`else`
`274`	`276`	`{`
`275`	`277`	`if (GetDatabaseEncoding() == PG_UTF8)`
`276`		`- pg_regex_strategy = PG_REGEX_STRATEGY_LIBC_WIDE;`
	`278`	`+ strategy = PG_REGEX_STRATEGY_LIBC_WIDE;`
`277`	`279`	`else`
`278`		`- pg_regex_strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;`
	`280`	`+ strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;`
`279`	`281`	`}`
`280`		`-`
`281`		`- pg_regex_collation = collation;`
`282`	`282`	`}`
	`283`	`+`
	`284`	`+ pg_regex_strategy = strategy;`
	`285`	`+ pg_regex_locale = locale;`
	`286`	`+ pg_regex_collation = collation;`
`283`	`287`	`}`
`284`	`288`
`285`	`289`	`static int`