From: Mark Thom <markjordanthom@gmail.com>
Date: Wed, 23 Jul 2025 03:16:24 +0000 (-0700)
Subject: detect end_of_file before end_of_stream in get_char (#2990)
X-Git-Tag: v0.10.0~35^2~2
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=9b293cf1b601ca1fd2a00e8645cc89a795c34b0c;p=scryer-prolog.git

detect end_of_file before end_of_stream in get_char (#2990)
---

diff --git a/src/machine/system_calls.rs b/src/machine/system_calls.rs
index d301a85a..6c861ae6 100644
--- a/src/machine/system_calls.rs
+++ b/src/machine/system_calls.rs
@@ -3545,24 +3545,22 @@ impl Machine {
 
             self.machine_st.unify_atom(end_of_file, addr);
 
+            return Ok(());
+        } else if addr == atom_as_cell!(atom!("end_of_file")) {
+            self.machine_st.fail = true;
             return Ok(());
         }
 
         let stub_gen = || functor_stub(atom!("get_char"), 2);
-        let result = self.machine_st.open_parsing_stream(stream);
 
         let addr = if addr.is_var() {
             addr
         } else {
             read_heap_cell!(addr,
                 (HeapCellValueTag::Atom, (atom, _arity)) => {
-                    char_as_cell!(atom.as_char().unwrap())
-                }
-                /*
-                (HeapCellValueTag::Char) => {
+                    debug_assert!(atom.as_char().is_some());
                     addr
                 }
-                */
                 _ => {
                     let err = self.machine_st.type_error(ValidType::InCharacter, addr);
                     return Err(self.machine_st.error_form(err, stub_gen()));
@@ -3570,7 +3568,7 @@ impl Machine {
             )
         };
 
-        let mut iter = match result {
+        let mut iter = match self.machine_st.open_parsing_stream(stream) {
             Ok(iter) => iter,
             Err(e) => {
                 if e.is_unexpected_eof() {