Merged revisions 22977 via svnmerge from

https://lampsvn.epfl.ch/svn-repos/scala/scala/trunk

........
  r22977 | moors | 2010-09-14 14:11:54 +0200 (Tue, 14 Sep 2010) | 5 lines

  relax implicit divergence check

  patch contributed by Mark Harrah in
http://article.gmane.org/gmane.comp.lang.scala/20700

  reviewed by moors and odersky
........

4 files changed, 11 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
index 42c1329edf..28c4b67db9 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
@@ -102,7 +102,7 @@ trait Contexts { self: Analyzer =>
                                                     // not inherited to child contexts
     var depth: Int = 0
     var imports: List[ImportInfo] = List()   // currently visible imports
-    var openImplicits: List[Type] = List()   // types for which implicit arguments
+    var openImplicits: List[(Type,Symbol)] = List()   // types for which implicit arguments
                                              // are currently searched
     // for a named application block (Tree) the corresponding NamedApplyInfo
     var namedApplyBlockInfo: Option[(Tree, NamedApplyInfo)] = None
diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
index 63b971d2fd..adcae7d9b1 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
@@ -344,14 +344,14 @@ self: Analyzer =>
      *  @pre           <code>info.tpe</code> does not contain an error
      */
     private def typedImplicit(info: ImplicitInfo): SearchResult =
-       context.openImplicits find (dominates(pt, _)) match {
+      (context.openImplicits find { case (tp, sym) => sym == tree.symbol && dominates(pt, tp)}) match {
          case Some(pending) =>
            // println("Pending implicit "+pending+" dominates "+pt+"/"+undetParams) //@MDEBUG
            throw DivergentImplicit
            SearchFailure
          case None =>
            try {
-             context.openImplicits = pt :: context.openImplicits
+             context.openImplicits = (pt, tree.symbol) :: context.openImplicits
              // println("  "*context.openImplicits.length+"typed implicit "+info+" for "+pt) //@MDEBUG
              typedImplicit0(info)
            } catch {
diff --git a/test/files/neg/t0226.check b/test/files/neg/t0226.check
index e27ffbc1e1..af81e41a6a 100644
--- a/test/files/neg/t0226.check
+++ b/test/files/neg/t0226.check
@@ -4,8 +4,7 @@ t0226.scala:5: error: not found: type A1
 t0226.scala:5: error: not found: type A1
       (implicit _1: Foo[List[A1]], _2: Foo[A2]): Foo[Tuple2[List[A1], A2]] =
                              ^
-t0226.scala:8: error: diverging implicit expansion for type Test.this.Foo[((List[Char], Int), (object Nil, Int))]
-starting with method list2Foo in class Test
+t0226.scala:8: error: could not find implicit value for parameter rep: Test.this.Foo[((List[Char], Int), (object Nil, Int))]
   foo(((List('b'), 3), (Nil, 4)))
      ^
 three errors found
diff --git a/test/files/pos/relax_implicit_divergence.scala b/test/files/pos/relax_implicit_divergence.scala
new file mode 100644
index 0000000000..8525c84bab
--- /dev/null
+++ b/test/files/pos/relax_implicit_divergence.scala
@@ -0,0 +1,7 @@
+class A(val options: Seq[String])
+
+object Test {
+  implicit def ss: Equiv[Seq[String]] = error("dummy")
+  implicit def equivA(implicit seqEq: Equiv[Seq[String]]): Equiv[A] = error("dummy")
+  implicitly[Equiv[A]]
+}
\ No newline at end of file