Fix alias infinite loop

Author: ryuichiueda

src/core.rs

@@ -236,6 +236,7 @@ impl ShellCore {
 
         let mut ans = false;
         let mut prev_head = "".to_string();
+        let history = vec![word.clone()];
 
         loop {
             let head = match word.replace("\n", " ").split(' ').nth(0) {
@@ -249,6 +250,9 @@ impl ShellCore {
 
             if let Some(value) = self.aliases.get(&head) {
                 *word = word.replacen(&head, value, 1);
+                if history.contains(word) {
+                    return false;
+                }
                 ans = true;
             }
             prev_head = head;

src/elements/command/simple.rs

@@ -24,6 +24,7 @@ pub struct SimpleCommand {
     substitutions_as_args: Vec<Substitution>,
     command_name: String,
     lineno: usize,
+    continue_alias_check: bool,
 }
 
 

src/elements/command/simple/parser.rs

@@ -44,8 +44,8 @@ impl SimpleCommand {
             ans.command_name = w.text.clone();
         }
 
-        if ans.words.is_empty() {
-            if Self::set_alias(&w, &mut ans.words, &mut ans.text, core, feeder)? {
+        if ans.words.is_empty() || ans.continue_alias_check {
+            if ans.set_alias(&w, core, feeder)? {
                 return Ok(true);
             }
         }
@@ -56,26 +56,29 @@ impl SimpleCommand {
         Ok(true)
     }
 
-    fn set_alias(word: &Word, words: &mut Vec<Word>, text: &mut String,
+    fn set_alias(&mut self, word: &Word,
                  core: &mut ShellCore, feeder: &mut Feeder) -> Result<bool, ParseError> {
+        self.continue_alias_check = false;
         let mut w = word.text.clone();
         if ! core.replace_alias(&mut w) {
             return Ok(false);
         }
 
+        self.continue_alias_check = w.ends_with(" ");
+
         let mut feeder_local = Feeder::new(&mut w);
         loop {
             match Word::parse(&mut feeder_local, core, None) {
                 Ok(Some(w)) => {
-                    text.push_str(&w.text);
-                    words.push(w);
+                    self.text.push_str(&w.text);
+                    self.words.push(w);
                 },
                 _    => break,
             }
-            command::eat_blank_with_comment(&mut feeder_local, core, text);
+            command::eat_blank_with_comment(&mut feeder_local, core, &mut self.text);
         }
 
-        if words.is_empty() {
+        if self.words.is_empty() {
             return Err(ParseError::WrongAlias(w));
         }