Clean up cross-check in classfile parser, remove unnecessary assignment

One of the first entries in the classfile is the class name. The
classfile parser performs a cross-check by looking up the class sybmol
corresponding to that name and ensures it's the same as `clazz`, the
class symbol that the parser currently populates.

Since 322c980 ("Another massive IDE checkin"), if at the time of the
check `clazz` but the lookup returns some class, the `clazz` field is
assigned.

The commit following this one makes sure `clazz` is never NoSymbol, so
the assignment can safely be removed.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
index e96be74ba1..e69c9f816a 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
@@ -421,13 +421,10 @@ abstract class ClassfileParser {
     }
 
     val isTopLevel = !(currentClass containsChar '$') // Java class name; *don't* try to to use Scala name decoding (SI-7532)
-
-    val c = if (isTopLevel) pool.getClassSymbol(nameIdx) else clazz
     if (isTopLevel) {
-      if (c != clazz) {
-        if ((clazz eq NoSymbol) && (c ne NoSymbol)) clazz = c
-        else mismatchError(c)
-      }
+      val c = pool.getClassSymbol(nameIdx)
+      // scala-dev#248: when a type alias (in a package object) shadows a class symbol, getClassSymbol returns a stub
+      if (!c.isInstanceOf[StubSymbol] && c != clazz) mismatchError(c)
     }
 
     addEnclosingTParams(clazz)