Fix panic and infinite loop in parser (#4149)

core/src/syn/common.rs

@@ -88,6 +88,23 @@ impl Location {
 	}
 
 	pub fn range_of_span(source: &str, span: Span) -> Range<Self> {
+		if source.len() == span.offset as usize {
+			// EOF span
+			let (line_idx, column) = LineIterator::new(source)
+				.map(|(l, _)| l.len())
+				.enumerate()
+				.last()
+				.unwrap_or((0, 0));
+
+			return Self {
+				line: line_idx + 1,
+				column: column + 1,
+			}..Self {
+				line: line_idx + 1,
+				column: column + 2,
+			};
+		}
+
 		// Bytes of input before substr.
 		let offset = span.offset as usize;
 		let end = offset + span.len as usize;

core/src/syn/lexer/mod.rs

@@ -213,8 +213,8 @@ impl<'a> Lexer<'a> {
 		Token {
 			kind: TokenKind::Eof,
 			span: Span {
-				offset: self.last_offset.saturating_sub(1),
-				len: 1,
+				offset: self.last_offset,
+				len: 0,
 			},
 		}
 	}

core/src/syn/parser/prime.rs

@@ -344,7 +344,6 @@ impl Parser<'_> {
 		match peek.kind {
 			t!("(") => {
 				self.pop_peek();
-				dbg!("called");
 				self.parse_inner_subquery(ctx, Some(peek.span)).await
 			}
 			t!("IF") => {

core/src/syn/parser/stmt/mod.rs

@@ -42,7 +42,10 @@ impl Parser<'_> {
 		loop {
 			match self.peek_kind() {
 				// consume any possible empty statements.
-				t!(";") => continue,
+				t!(";") => {
+					self.pop_peek();
+					continue;
+				}
 				t!("eof") => break,
 				_ => {
 					let stmt = ctx.run(|ctx| self.parse_stmt(ctx)).await?;

core/src/syn/parser/test/mod.rs

@@ -1,4 +1,13 @@
+use crate::{sql, syn::parser::mac::test_parse};
+
 mod limit;
 mod stmt;
 mod streaming;
 mod value;
+
+#[test]
+fn multiple_semicolons() {
+	let res = test_parse!(parse_query, r#";;"#).unwrap();
+	let expected = sql::Query(sql::Statements(vec![]));
+	assert_eq!(res, expected);
+}

core/src/syn/parser/test/value.rs

@@ -167,3 +167,8 @@ fn scientific_number() {
 	assert!(matches!(res, Value::Number(Number::Float(_))));
 	assert_eq!(res.to_string(), "0.000097f")
 }
+
+#[test]
+fn empty_string() {
+	test_parse!(parse_value, "").unwrap_err();
+}