fixed some problems with positions.

1 files changed, 13 insertions, 11 deletions

diff --git a/src/compiler/scala/tools/nsc/interactive/ContextTrees.scala b/src/compiler/scala/tools/nsc/interactive/ContextTrees.scala
index 5ed0581bdf..8d188cac62 100755
--- a/src/compiler/scala/tools/nsc/interactive/ContextTrees.scala
+++ b/src/compiler/scala/tools/nsc/interactive/ContextTrees.scala
@@ -23,7 +23,7 @@ trait ContextTrees { self: Global =>
     override def toString = "ContextTree("+pos+", "+children+")"
   }
 
-  /** Optionally return the smallest context taht contains given `pos`, or None if none exists.
+  /** Optionally return the smallest context that contains given `pos`, or None if none exists.
    */
   def locateContext(contexts: Contexts, pos: Position): Option[Context] = {
     if (contexts.isEmpty) None
@@ -32,17 +32,17 @@ trait ContextTrees { self: Global =>
       if ((contexts(hi).pos precedes pos) || (pos precedes contexts(0).pos)) None
       else {
         def loop(lo: Int, hi: Int): Option[Context] = {
-          assert(lo <= hi)
           val mid = (lo + hi) / 2
           val midpos = contexts(mid).pos
-          if (pos precedes midpos)
-            loop(lo, mid - 1)
-          else if (midpos precedes pos)
-            loop(mid + 1, hi)
+          if ((pos precedes midpos) && (mid < hi))
+            loop(lo, mid)
+          else if ((midpos precedes pos) && (lo < mid))
+            loop(mid, hi)
           else if (midpos includes pos)
-            locateContext(contexts(mid).children, pos) orElse Some(contexts(mid).context)
-          else
-            None
+            Some(contexts(mid).context)
+          else if (contexts(mid+1).pos includes pos)
+            Some(contexts(mid+1).context)
+          else None
         }
         loop(0, hi)
       }
@@ -74,7 +74,7 @@ trait ContextTrees { self: Global =>
         if (contexts(hi).pos properlyPrecedes cpos)
           contexts += new ContextTree(cpos, context)
         else if (contexts(hi).pos properlyIncludes cpos) // fast path w/o search
-          addContext(contexts(hi).children, context)
+          addContext(contexts(hi).children, context, cpos)
         else if (cpos properlyPrecedes contexts(0).pos)
           new ContextTree(cpos, context) +: contexts
         else {
@@ -84,7 +84,7 @@ trait ContextTrees { self: Global =>
               contexts(idx) = new ContextTree(cpos, context, contexts(idx).children)
               true
             } else if (oldpos includes cpos) {
-              addContext(contexts(idx).children, context)
+              addContext(contexts(idx).children, context, cpos)
               true
             } else if (cpos includes oldpos) {
               val start = contexts.indexWhere(cpos includes _.pos)
@@ -116,6 +116,8 @@ trait ContextTrees { self: Global =>
       }
     } catch {
       case ex: Throwable =>
+        println(ex)
+        ex.printStackTrace()
         println("failure inserting "+cpos+" into "+contexts+"/"+contexts(contexts.length - 1).pos+"/"+
                 (contexts(contexts.length - 1).pos includes cpos))
         throw ex