fix(parser): Don't panic on bad hex characters

Author: epage

crates/toml_parser/src/decoder/scalar.rs

@@ -561,7 +561,7 @@ fn decode_float_or_integer<'i>(
 
             if 0 < part_start {
                 let first = part.as_bytes().first().copied().unwrap_or(b'0');
-                if !is_any_digit(first, kind) {
+                if first == b'_' {
                     let start = part_start - 1;
                     let end = part_start;
                     debug_assert_eq!(&raw.as_str()[start..end], underscore);
@@ -574,7 +574,7 @@ fn decode_float_or_integer<'i>(
             }
             if 1 < part.len() && part_end < raw.len() {
                 let last = part.as_bytes().last().copied().unwrap_or(b'0');
-                if !is_any_digit(last, kind) {
+                if last == b'_' {
                     let start = part_end;
                     let end = start + underscore.len();
                     debug_assert_eq!(&raw.as_str()[start..end], underscore);
@@ -615,22 +615,6 @@ fn decode_float_or_integer<'i>(
     kind
 }
 
-fn is_any_digit(b: u8, kind: ScalarKind) -> bool {
-    if kind == ScalarKind::Float {
-        is_dec_integer_digit(b)
-    } else {
-        is_any_integer_digit(b)
-    }
-}
-
-fn is_any_integer_digit(b: u8) -> bool {
-    (b'0'..=b'9', b'a'..=b'f', b'A'..=b'F').contains_token(b)
-}
-
-fn is_dec_integer_digit(b: u8) -> bool {
-    (b'0'..=b'9').contains_token(b)
-}
-
 fn has_underscore(raw: &str) -> bool {
     raw.as_bytes().find_slice(b'_').is_some()
 }

crates/toml_parser/tests/snapshots/testsuite__parse_document__hex_with_bad_chars.txt

@@ -0,0 +1,64 @@
+EventResults {
+    input: "\nv=0xz_\n",
+    events: [
+        Event {
+            kind: Newline,
+            encoding: None,
+            span: 0..1,
+        },
+        Event {
+            kind: SimpleKey,
+            encoding: None,
+            span: 1..2,
+        },
+        Event {
+            kind: KeyValSep,
+            encoding: None,
+            span: 2..3,
+        },
+        Event {
+            kind: Scalar,
+            encoding: None,
+            span: 3..7,
+        },
+        Event {
+            kind: Newline,
+            encoding: None,
+            span: 7..8,
+        },
+    ],
+    errors: [
+        ParseError {
+            context: Some(
+                3..7,
+            ),
+            description: "invalid hexadecimal number",
+            expected: None,
+            unexpected: Some(
+                5..5,
+            ),
+        },
+        ParseError {
+            context: Some(
+                3..7,
+            ),
+            description: "`_` may only go between digits",
+            expected: Some(
+                [],
+            ),
+            unexpected: Some(
+                6..7,
+            ),
+        },
+        ParseError {
+            context: Some(
+                0..4,
+            ),
+            description: "failed to parse i64",
+            expected: None,
+            unexpected: Some(
+                0..2,
+            ),
+        },
+    ],
+}

crates/toml_parser/tests/testsuite/parse_document.rs

@@ -494,7 +494,6 @@ v=0x _
 }
 
 #[test]
-#[should_panic]
 fn hex_with_bad_chars() {
     t(
         "