Fix the dollar sign so it properly handles reserved keywords

The dollar sign would sometimes be accepted as whitespace if it was
immediately followed by a reserved keyword or an invalid character. It
now reads these properly as a bound parameter rather than ignoring the
dollar sign.

CHANGELOG.md

@@ -16,7 +16,8 @@
 - [#1834](https://github.com/influxdata/influxdb/issues/1834): Drop time when used as a tag or field key.
 - [#7152](https://github.com/influxdata/influxdb/issues/7152): Decrement number of measurements only once when deleting the last series from a measurement.
 - [#7177](https://github.com/influxdata/influxdb/issues/7177): Fix base64 encoding issue with /debug/vars stats.
-- [#7196](https://github.com/influxdata/influxdb/ssues/7196): Fix mmap dereferencing, fixes #7183, #7180
+- [#7196](https://github.com/influxdata/influxdb/issues/7196): Fix mmap dereferencing, fixes #7183, #7180
+- [#7013](https://github.com/influxdata/influxdb/issues/7013): Fix the dollar sign so it properly handles reserved keywords.
 
 ## v1.0.0 [unreleased]
 

influxql/parser.go

@@ -2409,9 +2409,14 @@ func (p *Parser) parseUnaryExpr() (Expr, error) {
 		}
 		return &RegexLiteral{Val: re}, nil
 	case BOUNDPARAM:
-		v, ok := p.params[lit]
+		k := strings.TrimPrefix(lit, "$")
+		if len(k) == 0 {
+			return nil, errors.New("empty bound parameter")
+		}
+
+		v, ok := p.params[k]
 		if !ok {
-			return nil, fmt.Errorf("missing parameter: %s", lit)
+			return nil, fmt.Errorf("missing parameter: %s", k)
 		}
 
 		switch v := v.(type) {

influxql/parser_test.go

@@ -2308,6 +2308,8 @@ func TestParser_ParseStatement(t *testing.T) {
 		{s: `SET PASSWORD FOR dejan`, err: `found EOF, expected = at line 1, char 24`},
 		{s: `SET PASSWORD FOR dejan =`, err: `found EOF, expected string at line 1, char 25`},
 		{s: `SET PASSWORD FOR dejan = bla`, err: `found bla, expected string at line 1, char 26`},
+		{s: `$SHOW$DATABASES`, err: `found $SHOW, expected SELECT, DELETE, SHOW, CREATE, DROP, GRANT, REVOKE, ALTER, SET, KILL at line 1, char 1`},
+		{s: `SELECT * FROM cpu WHERE "tagkey" = $$`, err: `empty bound parameter`},
 	}
 
 	for i, tt := range tests {

influxql/scanner.go

@@ -32,7 +32,7 @@ func (s *Scanner) Scan() (tok Token, pos Pos, lit string) {
 		return s.scanWhitespace()
 	} else if isLetter(ch0) || ch0 == '_' {
 		s.r.unread()
-		return s.scanIdent()
+		return s.scanIdent(true)
 	} else if isDigit(ch0) {
 		return s.scanNumber()
 	}
@@ -43,7 +43,7 @@ func (s *Scanner) Scan() (tok Token, pos Pos, lit string) {
 		return EOF, pos, ""
 	case '"':
 		s.r.unread()
-		return s.scanIdent()
+		return s.scanIdent(true)
 	case '\'':
 		return s.scanString()
 	case '.':
@@ -54,11 +54,11 @@ func (s *Scanner) Scan() (tok Token, pos Pos, lit string) {
 		}
 		return DOT, pos, ""
 	case '$':
-		tok, _, lit := s.scanIdent()
-		if tok == IDENT {
-			tok = BOUNDPARAM
+		tok, _, lit = s.scanIdent(false)
+		if tok != IDENT {
+			return tok, pos, "$" + lit
 		}
-		return tok, pos, lit
+		return BOUNDPARAM, pos, "$" + lit
 	case '+', '-':
 		return s.scanNumber()
 	case '*':
@@ -135,7 +135,7 @@ func (s *Scanner) scanWhitespace() (tok Token, pos Pos, lit string) {
 	return WS, pos, buf.String()
 }
 
-func (s *Scanner) scanIdent() (tok Token, pos Pos, lit string) {
+func (s *Scanner) scanIdent(lookup bool) (tok Token, pos Pos, lit string) {
 	// Save the starting position of the identifier.
 	_, pos = s.r.read()
 	s.r.unread()
@@ -161,10 +161,11 @@ func (s *Scanner) scanIdent() (tok Token, pos Pos, lit string) {
 	lit = buf.String()
 
 	// If the literal matches a keyword then return that keyword.
-	if tok = Lookup(lit); tok != IDENT {
-		return tok, pos, ""
+	if lookup {
+		if tok = Lookup(lit); tok != IDENT {
+			return tok, pos, ""
+		}
 	}
-
 	return IDENT, pos, lit
 }
 

influxql/scanner_test.go

@@ -70,8 +70,8 @@ func TestScanner_Scan(t *testing.T) {
 		{s: `"foo\"bar\""`, tok: influxql.IDENT, lit: `foo"bar"`},
 		{s: `test"`, tok: influxql.BADSTRING, lit: "", pos: influxql.Pos{Line: 0, Char: 3}},
 		{s: `"test`, tok: influxql.BADSTRING, lit: `test`},
-		{s: `$host`, tok: influxql.BOUNDPARAM, lit: `host`},
-		{s: `$"host param"`, tok: influxql.BOUNDPARAM, lit: `host param`},
+		{s: `$host`, tok: influxql.BOUNDPARAM, lit: `$host`},
+		{s: `$"host param"`, tok: influxql.BOUNDPARAM, lit: `$host param`},
 
 		{s: `true`, tok: influxql.TRUE},
 		{s: `false`, tok: influxql.FALSE},