Tighten checks for whitespace in functions that parse identifiers etc.

tglsfdc · tglsfdc · commit 8527132e5278 · 2017-05-24T15:28:34.000-04:00
This patch replaces isspace() calls with scanner_isspace() in functions that are likely to be presented with non-ASCII input. isspace() has the small advantage that it will correctly recognize no-break space in single-byte encodings (such as LATIN1); but it cannot work successfully for any multibyte character, and depending on platform it might return false positive results for some fragments of multibyte characters. That's disastrous for functions that are trying to discard whitespace between valid strings, as noted in bug #14662 from Justin Muise. Even treating no-break space as whitespace is pretty questionable for the usages touched here, because the core scanner would think it is an identifier character. Affected functions are parse_ident(), parseNameAndArgTypes (underlying regprocedurein() and siblings), SplitIdentifierString (used for parsing GUCs and options that are qualified names or lists of names), and SplitDirectoriesString (used for parsing GUCs that are lists of directories). All the functions adjusted here are parsing SQL identifiers and similar constructs, so it's reasonable to insist that their definition of whitespace match the core scanner. So we can hope that this won't cause many backwards-compatibility problems. I've left alone isspace() calls in places that aren't really expecting any non-ASCII input characters, such as float8in(). Back-patch to all supported branches. Discussion: https://postgr.es/m/10129.1495302480@sss.pgh.pa.us
diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
@@ -775,7 +775,7 @@ parse_ident(PG_FUNCTION_ARGS)
 	nextp = qualname_str;
 
 	/* skip leading whitespace */
-	while (isspace((unsigned char) *nextp))
+	while (scanner_isspace(*nextp))
 		nextp++;
 
 	for (;;)
@@ -863,14 +863,14 @@ parse_ident(PG_FUNCTION_ARGS)
 								text_to_cstring(qualname))));
 		}
 
-		while (isspace((unsigned char) *nextp))
+		while (scanner_isspace(*nextp))
 			nextp++;
 
 		if (*nextp == '.')
 		{
 			after_dot = true;
 			nextp++;
-			while (isspace((unsigned char) *nextp))
+			while (scanner_isspace(*nextp))
 				nextp++;
 		}
 		else if (*nextp == '\0')
diff --git a/src/backend/utils/adt/regproc.c b/src/backend/utils/adt/regproc.c
@@ -35,6 +35,7 @@
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "parser/parse_type.h"
+#include "parser/scansup.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
@@ -1911,7 +1912,7 @@ parseNameAndArgTypes(const char *string, bool allowNone, List **names,
 	ptr2 = ptr + strlen(ptr);
 	while (--ptr2 > ptr)
 	{
-		if (!isspace((unsigned char) *ptr2))
+		if (!scanner_isspace(*ptr2))
 			break;
 	}
 	if (*ptr2 != ')')
@@ -1928,7 +1929,7 @@ parseNameAndArgTypes(const char *string, bool allowNone, List **names,
 	for (;;)
 	{
 		/* allow leading whitespace */
-		while (isspace((unsigned char) *ptr))
+		while (scanner_isspace(*ptr))
 			ptr++;
 		if (*ptr == '\0')
 		{
@@ -1984,7 +1985,7 @@ parseNameAndArgTypes(const char *string, bool allowNone, List **names,
 		/* Lop off trailing whitespace */
 		while (--ptr2 >= typename)
 		{
-			if (!isspace((unsigned char) *ptr2))
+			if (!scanner_isspace(*ptr2))
 				break;
 			*ptr2 = '\0';
 		}
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
@@ -3133,7 +3133,7 @@ SplitIdentifierString(char *rawstring, char separator,
 
 	*namelist = NIL;
 
-	while (isspace((unsigned char) *nextp))
+	while (scanner_isspace(*nextp))
 		nextp++;				/* skip leading whitespace */
 
 	if (*nextp == '\0')
@@ -3171,7 +3171,7 @@ SplitIdentifierString(char *rawstring, char separator,
 
 			curname = nextp;
 			while (*nextp && *nextp != separator &&
-				   !isspace((unsigned char) *nextp))
+				   !scanner_isspace(*nextp))
 				nextp++;
 			endp = nextp;
 			if (curname == nextp)
@@ -3193,13 +3193,13 @@ SplitIdentifierString(char *rawstring, char separator,
 			pfree(downname);
 		}
 
-		while (isspace((unsigned char) *nextp))
+		while (scanner_isspace(*nextp))
 			nextp++;			/* skip trailing whitespace */
 
 		if (*nextp == separator)
 		{
 			nextp++;
-			while (isspace((unsigned char) *nextp))
+			while (scanner_isspace(*nextp))
 				nextp++;		/* skip leading whitespace for next */
 			/* we expect another name, so done remains false */
 		}
@@ -3258,7 +3258,7 @@ SplitDirectoriesString(char *rawstring, char separator,
 
 	*namelist = NIL;
 
-	while (isspace((unsigned char) *nextp))
+	while (scanner_isspace(*nextp))
 		nextp++;				/* skip leading whitespace */
 
 	if (*nextp == '\0')
@@ -3295,21 +3295,21 @@ SplitDirectoriesString(char *rawstring, char separator,
 			while (*nextp && *nextp != separator)
 			{
 				/* trailing whitespace should not be included in name */
-				if (!isspace((unsigned char) *nextp))
+				if (!scanner_isspace(*nextp))
 					endp = nextp + 1;
 				nextp++;
 			}
 			if (curname == endp)
 				return false;	/* empty unquoted name not allowed */
 		}
 
-		while (isspace((unsigned char) *nextp))
+		while (scanner_isspace(*nextp))
 			nextp++;			/* skip trailing whitespace */
 
 		if (*nextp == separator)
 		{
 			nextp++;
-			while (isspace((unsigned char) *nextp))
+			while (scanner_isspace(*nextp))
 				nextp++;		/* skip leading whitespace for next */
 			/* we expect another name, so done remains false */
 		}

Original file line number	Diff line number	Diff line change
`@@ -35,6 +35,7 @@`
`35`	`35`	`#include "lib/stringinfo.h"`
`36`	`36`	`#include "miscadmin.h"`
`37`	`37`	`#include "parser/parse_type.h"`
	`38`	`+#include "parser/scansup.h"`
`38`	`39`	`#include "utils/builtins.h"`
`39`	`40`	`#include "utils/fmgroids.h"`
`40`	`41`	`#include "utils/lsyscache.h"`
`@@ -1911,7 +1912,7 @@ parseNameAndArgTypes(const char string, bool allowNone, List *names,`
`1911`	`1912`	`ptr2 = ptr + strlen(ptr);`
`1912`	`1913`	`while (--ptr2 > ptr)`
`1913`	`1914`	`{`
`1914`		`- if (!isspace((unsigned char) *ptr2))`
	`1915`	`+ if (!scanner_isspace(*ptr2))`
`1915`	`1916`	`break;`
`1916`	`1917`	`}`
`1917`	`1918`	`if (*ptr2 != ')')`
`@@ -1928,7 +1929,7 @@ parseNameAndArgTypes(const char string, bool allowNone, List *names,`
`1928`	`1929`	`for (;;)`
`1929`	`1930`	`{`
`1930`	`1931`	`/* allow leading whitespace */`
`1931`		`- while (isspace((unsigned char) *ptr))`
	`1932`	`+ while (scanner_isspace(*ptr))`
`1932`	`1933`	`ptr++;`
`1933`	`1934`	`if (*ptr == '\0')`
`1934`	`1935`	`{`
`@@ -1984,7 +1985,7 @@ parseNameAndArgTypes(const char string, bool allowNone, List *names,`
`1984`	`1985`	`/* Lop off trailing whitespace */`
`1985`	`1986`	`while (--ptr2 >= typename)`
`1986`	`1987`	`{`
`1987`		`- if (!isspace((unsigned char) *ptr2))`
	`1988`	`+ if (!scanner_isspace(*ptr2))`
`1988`	`1989`	`break;`
`1989`	`1990`	`*ptr2 = '\0';`
`1990`	`1991`	`}`