fix escape code leak

parse_test.rs

@@ -0,0 +1,2 @@
+use zterm::vt_parser::*;
+fn main() {}

src/lib.rs

@@ -20,3 +20,4 @@ pub mod statusline;
 pub mod terminal;
 pub mod simd_utf8;
 pub mod vt_parser;
+mod vt_test_osc;

src/vt_parser.rs

@@ -482,7 +482,9 @@ impl SharedParser {
 
             // Like Kitty line 1516: consume_input(self, ...)
             let made_progress = self.consume_input(handler);
+            if made_progress {
                 parsed_any = true;
+            }
 
             // Re-acquire lock
             state = self.state.lock().unwrap();
@@ -635,14 +637,14 @@ impl SharedParser {
                 true
             }
             State::Csi => {
-                // Like Kitty lines 1465-1466:
+                let state_before = *vte_state;
-                // if (consume_csi(self)) { self->read.consumed = self->read.pos; if (self->csi.is_valid) dispatch_csi(self); SET_STATE(NORMAL); }
                 if Self::consume_csi_impl(
                     handler,
                     buf,
                     parse_pos,
                     parse_sz,
-                    *parse_consumed,
+                    parse_consumed,
+                    vte_state,
                     csi,
                     escape_len,
                 ) {
@@ -650,30 +652,41 @@ impl SharedParser {
                     if csi.is_valid {
                         handler.csi(csi);
                     }
+                    if *vte_state == state_before {
                         *vte_state = State::Normal;
+                    }
                     true
                 } else {
-                    false
+                    *vte_state != state_before
                 }
             }
             State::Osc => {
+                let state_before = *vte_state;
                 if Self::consume_osc_impl(
-                    handler, buf, parse_pos, parse_sz, vte_state, osc_buffer,
+                    handler,
+                    buf,
+                    parse_pos,
+                    parse_sz,
+                    parse_consumed,
+                    vte_state,
+                    osc_buffer,
                     escape_len,
                 ) {
                     *parse_consumed = *parse_pos;
                     *vte_state = State::Normal;
                     true
                 } else {
-                    false
+                    *vte_state != state_before
                 }
             }
             State::Dcs | State::Apc | State::Pm | State::Sos => {
+                let state_before = *vte_state;
                 if Self::consume_string_impl(
                     handler,
                     buf,
                     parse_pos,
                     parse_sz,
+                    parse_consumed,
                     vte_state,
                     string_buffer,
                     escape_len,
@@ -682,7 +695,7 @@ impl SharedParser {
                     *vte_state = State::Normal;
                     true
                 } else {
-                    false
+                    *vte_state != state_before
                 }
             }
         };
@@ -837,6 +850,11 @@ impl SharedParser {
                 b'\\' => {
                     *vte_state = State::Normal;
                 }
+                0x1B => {
+                    // ESC followed by ESC. Start new escape sequence.
+                    *vte_state = State::Escape;
+                    return true;
+                }
                 _ => {
                     log::debug!("Unknown escape sequence: ESC {:02x}", ch);
                     *vte_state = State::Normal;
@@ -913,7 +931,8 @@ impl SharedParser {
         buf: &[u8; BUF_SIZE],
         parse_pos: &mut usize,
         parse_sz: usize,
-        parse_consumed: usize,
+        parse_consumed: &mut usize,
+        vte_state: &mut State,
         csi: &mut CsiParams,
         escape_len: &mut usize,
     ) -> bool {
@@ -922,8 +941,15 @@ impl SharedParser {
             *parse_pos += 1;
             *escape_len += 1;
 
+            if ch == 0x1B {
+                *vte_state = State::Escape;
+                *parse_consumed = *parse_pos;
+                *escape_len = 0;
+                return false; // Aborted by new ESC
+            }
+
             // Handle embedded control characters
-            if ch <= 0x1F && ch != 0x1B {
+            if ch <= 0x1F {
                 handler.control(ch);
                 continue;
             }
@@ -1023,7 +1049,7 @@ impl SharedParser {
         }
 
         // Check max length
-        if *parse_pos - parse_consumed > MAX_ESCAPE_LEN {
+        if *parse_pos - *parse_consumed > MAX_ESCAPE_LEN {
             log::debug!("CSI escape too long, ignoring");
             return true;
         }
@@ -1037,6 +1063,7 @@ impl SharedParser {
         buf: &[u8; BUF_SIZE],
         parse_pos: &mut usize,
         parse_sz: usize,
+        parse_consumed: &mut usize,
         vte_state: &mut State,
         osc_buffer: &mut Vec<u8>,
         escape_len: &mut usize,
@@ -1069,6 +1096,7 @@ impl SharedParser {
                         *parse_pos += 1;
                         handler.osc(osc_buffer);
                         *vte_state = State::Escape;
+                        *parse_consumed = *parse_pos;
                         *escape_len = 0;
                         return false;
                     } else {
@@ -1098,6 +1126,7 @@ impl SharedParser {
         buf: &[u8; BUF_SIZE],
         parse_pos: &mut usize,
         parse_sz: usize,
+        parse_consumed: &mut usize,
         vte_state: &mut State,
         string_buffer: &mut Vec<u8>,
         escape_len: &mut usize,
@@ -1128,10 +1157,17 @@ impl SharedParser {
                         );
                         return true;
                     } else if *parse_pos + 1 < parse_sz {
-                        // ESC not followed by \ - include in buffer
+                        // ESC not followed by \ - abort string, start new escape
-                        string_buffer.push(ch);
                         *parse_pos += 1;
-                        *escape_len += 1;
+                        Self::dispatch_string_command(
+                            handler,
+                            vte_state,
+                            string_buffer,
+                        );
+                        *vte_state = State::Escape;
+                        *parse_consumed = *parse_pos;
+                        *escape_len = 0;
+                        return false;
                     } else {
                         // ESC at end of buffer - need more data
                         return false;
@@ -1368,6 +1404,11 @@ impl Parser {
                 self.state = State::Normal;
                 1
             }
+            0x1B => {
+                // ESC followed by ESC. Start new escape sequence.
+                self.state = State::Escape;
+                1
+            }
             _ => {
                 // Unknown escape sequence, ignore and return to normal
                 log::debug!("Unknown escape sequence: ESC {:02x}", ch);
@@ -1442,8 +1483,17 @@ impl Parser {
                 return consumed;
             }
 
+            if ch == 0x1B {
+                self.state = State::Escape;
+                self.escape_len = 0;
+                // Wait! If it's ESC, we consumed it. But the next loop in parse() will call consume_escape,
+                // which EXPECTS the char AFTER ESC.
+                // So consuming it is PERFECT!
+                return consumed;
+            }
+
             // Handle control characters embedded in CSI (common to all states)
-            if ch <= 0x1F && ch != 0x1B {
+            if ch <= 0x1F {
                 handler.control(ch);
                 continue;
             }

src/vt_test_osc.rs

@@ -0,0 +1,78 @@
+use crate::vt_parser::*;
+
+pub struct DummyHandler {
+    pub text: String,
+    pub osc_calls: Vec<Vec<u8>>,
+}
+impl Handler for DummyHandler {
+    fn text(&mut self, codepoints: &[u32]) {
+        for &c in codepoints {
+            if let Some(ch) = char::from_u32(c) {
+                self.text.push(ch);
+            }
+        }
+    }
+    fn control(&mut self, _byte: u8) {}
+    fn csi(&mut self, _csi: &CsiParams) {}
+    fn osc(&mut self, osc: &[u8]) {
+        self.osc_calls.push(osc.to_vec());
+    }
+    fn save_cursor(&mut self) {}
+    fn restore_cursor(&mut self) {}
+    fn reset(&mut self) {}
+    fn index(&mut self) {}
+    fn newline(&mut self) {}
+    fn reverse_index(&mut self) {}
+    fn screen_alignment(&mut self) {}
+    fn set_tab_stop(&mut self) {}
+    fn set_keypad_mode(&mut self, _mode: bool) {}
+    fn add_vt_parser_ns(&mut self, _ns: u64) {}
+}
+
+#[test]
+fn test_osc_leak_byte_by_byte() {
+    let parser = SharedParser::new();
+    let mut handler = DummyHandler { text: String::new(), osc_calls: Vec::new() };
+    
+    let data = b"\x1b]4;1;#769E00\x1b\\\x1b]4;2;#93DE88\x1b\\";
+    
+    for &byte in data {
+        let (ptr, _) = parser.create_write_buffer();
+        unsafe {
+            *ptr = byte;
+        }
+        parser.commit_write(1);
+        
+        while parser.run_parse_pass(&mut handler) {}
+    }
+    
+    println!("TEXT: {:?}", handler.text);
+    println!("OSC calls: {}", handler.osc_calls.len());
+    for call in &handler.osc_calls {
+        println!("  OSC: {:?}", std::str::from_utf8(call).unwrap());
+    }
+    
+    assert_eq!(handler.text, "", "Text should be empty, but leaked escape sequence bytes!");
+    assert_eq!(handler.osc_calls.len(), 2, "Should have parsed exactly two OSC calls");
+}
+
+#[test]
+fn test_csi_aborted_by_osc() {
+    let parser = SharedParser::new();
+    let mut handler = DummyHandler { text: String::new(), osc_calls: Vec::new() };
+    
+    // An incomplete CSI sequence aborted by an OSC sequence
+    let data = b"\x1b[38;2;255;0;0\x1b]4;1;#769E00\x1b\\";
+    
+    let (ptr, len) = parser.create_write_buffer();
+    assert!(len >= data.len());
+    unsafe {
+        std::ptr::copy_nonoverlapping(data.as_ptr(), ptr, data.len());
+    }
+    parser.commit_write(data.len());
+    
+    while parser.run_parse_pass(&mut handler) {}
+    
+    assert_eq!(handler.text, "", "Text should be empty, but leaked escape sequence bytes!");
+    assert_eq!(handler.osc_calls.len(), 1, "Should have parsed the OSC sequence even after aborting CSI");
+}