When parsing a source string, fail when the entire string is not parsed.

(For now only fail when parse_from_source_str is used to avoid
possible compatibility problems; parse_expr_from_source_str still
does not check.)

src/comp/syntax/parse/parser.rs

@@ -2622,6 +2622,9 @@ fn parse_from_source_str<T>(f: fn (p: parser) -> T,
 {
     let p = new_parser_from_source_str(sess, cfg, name, ss, source);
     let r = f(p);
+    if !p.reader.is_eof() {
+        p.reader.fatal("expected end-of-string");
+    }
     sess.chpos = p.reader.chpos;
     sess.byte_pos = sess.byte_pos + p.reader.pos;
     ret r;

src/test/compile-fail/qquote-2.rs

@@ -0,0 +1,48 @@
+// xfail-pretty
+
+use std;
+use rustc;
+
+import rustc::*;
+import std::io::*;
+
+import rustc::driver::diagnostic;
+import rustc::syntax::ast;
+import rustc::syntax::codemap;
+import rustc::syntax::parse::parser;
+import rustc::syntax::print::*;
+
+fn new_parse_sess() -> parser::parse_sess {
+  fail;
+}
+
+iface fake_ext_ctxt {
+    fn session() -> fake_session;
+}
+
+type fake_options = {cfg: ast::crate_cfg};
+
+type fake_session = {opts: @fake_options,
+                     parse_sess: parser::parse_sess};
+
+impl of fake_ext_ctxt for fake_session {
+    fn session() -> fake_session {self}
+}
+
+fn mk_ctxt() -> fake_ext_ctxt {
+    let opts : fake_options = {cfg: []};
+    {opts: @opts, parse_sess: new_parse_sess()} as fake_ext_ctxt
+}
+
+
+fn main() {
+    let ext_cx = mk_ctxt();
+
+    let stmt = #ast(stmt){let x int = 20;}; //! ERROR expected end-of-string
+    check_pp(*stmt,  pprust::print_stmt, "");
+}
+
+fn check_pp<T>(expr: T, f: fn(pprust::ps, T), expect: str) {
+    fail;
+}
+