Strip more encoding modifiers

Strip modifiers even if they are inside the encoding string.

Fixes #834

Author: madsmtm

crates/objc2-encode/CHANGELOG.md

@@ -18,6 +18,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
 * Relaxed assertions on `Encoding::Struct`/`Encoding::Union`'s name to allow
   unicode identifiers.
+* Strip more modifiers to allow encoding parsing to work on macOS 10.7.
 
 
 ## [4.1.0] - 2025-01-22

crates/objc2-encode/src/encoding.rs

@@ -254,8 +254,6 @@ impl Encoding {
     pub fn equivalent_to_str(&self, s: &str) -> bool {
         let mut parser = Parser::new(s);
 
-        parser.strip_leading_qualifiers();
-
         if let Some(()) = parser.expect_encoding(self, NestingLevel::new()) {
             // if the given encoding can be successfully removed from the
             // start and an empty string remains, they were fully equivalent!
@@ -784,6 +782,17 @@ mod tests {
             !"*c";
             !"^^c";
         }
+
+        // Regression test for https://github.com/madsmtm/objc2/issues/834.
+        fn modifiers_behind_pointers() {
+            Encoding::Pointer(&Encoding::Object);
+            "^@";
+            ~"^r@";
+            ~"rrr^rrrr@";
+            !"^^r@";
+            !"r@";
+            !"^@r"; // Unsure?
+        }
     }
 
     #[test]

crates/objc2-encode/src/encoding_box.rs

@@ -124,8 +124,6 @@ impl EncodingBox {
     /// Returns an error if the string was an ill-formatted encoding string.
     pub fn from_start_of_str(s: &mut &str) -> Result<Self, ParseError> {
         let mut parser = Parser::new(s);
-        parser.strip_leading_qualifiers();
-
         match parser.parse_encoding_or_none() {
             Err(ErrorKind::Unknown(b'0'..=b'9')) => {
                 let remaining = parser.remaining();
@@ -168,8 +166,6 @@ impl FromStr for EncodingBox {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let mut parser = Parser::new(s);
-        parser.strip_leading_qualifiers();
-
         parser
             .parse_encoding_or_none()
             .and_then(|enc| parser.expect_empty().map(|()| enc))

crates/objc2-encode/src/parse.rs

@@ -181,7 +181,7 @@ impl<'a> Parser<'a> {
 
 impl Parser<'_> {
     /// Strip leading qualifiers, if any.
-    pub(crate) fn strip_leading_qualifiers(&mut self) {
+    fn strip_leading_qualifiers(&mut self) {
         // TODO: Add API for accessing and outputting qualifiers.
         #[allow(clippy::byte_char_slices)]
         const QUALIFIERS: &[u8] = &[
@@ -270,6 +270,8 @@ impl Parser<'_> {
     }
 
     pub(crate) fn expect_encoding(&mut self, enc: &Encoding, level: NestingLevel) -> Option<()> {
+        self.strip_leading_qualifiers();
+
         match enc.helper() {
             Helper::Primitive(primitive) => {
                 match primitive {
@@ -426,6 +428,8 @@ impl Parser<'_> {
     }
 
     fn parse_inner(&mut self) -> Result<ParseInner> {
+        self.strip_leading_qualifiers();
+
         if self.is_empty() {
             return Ok(ParseInner::Empty);
         }