diff --git a/src/class.c b/src/class.c
index f1425c46f4fa..1c46c8441087 100644
--- a/src/class.c
+++ b/src/class.c
@@ -905,7 +905,12 @@ Dsymbol *ClassDeclaration::search(Loc loc, Identifier *ident, int flags)
     if (scope && !symtab)
     {   Scope *sc = scope;
         sc->mustsemantic++;
+        // If speculatively gagged, ungag now.
+        unsigned oldgag = global.gag;
+        if (global.isSpeculativeGagging())
+            global.gag = 0;
         semantic(sc);
+        global.gag = oldgag;
         sc->mustsemantic--;
     }
 
diff --git a/src/declaration.c b/src/declaration.c
index 222e46cb7740..ef1fc99932c5 100644
--- a/src/declaration.c
+++ b/src/declaration.c
@@ -503,7 +503,7 @@ void AliasDeclaration::semantic(Scope *sc)
         ScopeDsymbol::multiplyDefined(0, this, overnext);
     this->inSemantic = 0;
 
-    if (errors != global.errors)
+    if (global.gag && errors != global.errors)
         type = savedtype;
     return;
 
@@ -539,7 +539,7 @@ void AliasDeclaration::semantic(Scope *sc)
             assert(global.errors);
             s = NULL;
         }
-        if (errors != global.errors)
+        if (global.gag && errors != global.errors)
         {
             type = savedtype;
             overnext = savedovernext;
diff --git a/src/dsymbol.c b/src/dsymbol.c
index 505baf0c98bf..a6d22186457e 100644
--- a/src/dsymbol.c
+++ b/src/dsymbol.c
@@ -277,6 +277,23 @@ TemplateInstance *Dsymbol::inTemplateInstance()
     return NULL;
 }
 
+// Check if this function is a member of a template which has only been
+// instantiated speculatively, eg from inside is(typeof()).
+// Return the speculative template instance it is part of,
+// or NULL if not speculative.
+TemplateInstance *Dsymbol::isSpeculative()
+{
+    Dsymbol * par = parent;
+    while (par)
+    {
+        TemplateInstance *ti = par->isTemplateInstance();
+        if (ti && ti->speculative)
+            return ti;
+        par = par->toParent();
+    }
+    return NULL;
+}
+
 int Dsymbol::isAnonymous()
 {
     return ident ? 0 : 1;
diff --git a/src/dsymbol.h b/src/dsymbol.h
index 346bd9b50f63..f76d04bb76d3 100644
--- a/src/dsymbol.h
+++ b/src/dsymbol.h
@@ -137,6 +137,7 @@ struct Dsymbol : Object
     Dsymbol *toParent();
     Dsymbol *toParent2();
     TemplateInstance *inTemplateInstance();
+    TemplateInstance *isSpeculative();
 
     int dyncast() { return DYNCAST_DSYMBOL; }   // kludge for template.isSymbol()
 
diff --git a/src/expression.c b/src/expression.c
index 6fabea9da5c1..8cf777890c9b 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -1,6 +1,6 @@
 
 // Compiler implementation of the D programming language
-// Copyright (c) 1999-2011 by Digital Mars
+// Copyright (c) 1999-2012 by Digital Mars
 // All Rights Reserved
 // written by Walter Bright
 // http://www.digitalmars.com
@@ -670,23 +670,6 @@ Expression *callCpCtor(Loc loc, Scope *sc, Expression *e, int noscope)
 }
 #endif
 
-// Check if this function is a member of a template which has only been
-// instantiated speculatively, eg from inside is(typeof()).
-// Return the speculative template instance it is part of,
-// or NULL if not speculative.
-TemplateInstance *isSpeculativeFunction(FuncDeclaration *fd)
-{
-    Dsymbol * par = fd->parent;
-    while (par)
-    {
-        TemplateInstance *ti = par->isTemplateInstance();
-        if (ti && ti->speculative)
-            return ti;
-        par = par->toParent();
-    }
-    return NULL;
-}
-
 /****************************************
  * Now that we know the exact type of the function we're calling,
  * the arguments[] need to be adjusted:
@@ -716,7 +699,7 @@ Type *functionParameters(Loc loc, Scope *sc, TypeFunction *tf,
     // If inferring return type, and semantic3() needs to be run if not already run
     if (!tf->next && fd->inferRetType)
     {
-        TemplateInstance *spec = isSpeculativeFunction(fd);
+        TemplateInstance *spec = fd->isSpeculative();
         int olderrs = global.errors;
         fd->semantic3(fd->scope);
         // Update the template instantiation with the number
@@ -2737,12 +2720,18 @@ Expression *DsymbolExp::semantic(Scope *sc)
     {   //printf("'%s' is a function\n", f->toChars());
 
         if (!f->originalType && f->scope)       // semantic not yet run
+        {
+            unsigned oldgag = global.gag;
+            if (global.isSpeculativeGagging() && !f->isSpeculative())
+                global.gag = 0;
             f->semantic(f->scope);
+            global.gag = oldgag;
+        }
 
         // if inferring return type, sematic3 needs to be run
         if (f->inferRetType && f->scope && f->type && !f->type->nextOf())
         {
-            TemplateInstance *spec = isSpeculativeFunction(f);
+            TemplateInstance *spec = f->isSpeculative();
             int olderrs = global.errors;
             f->semantic3(f->scope);
             // Update the template instantiation with the number
@@ -9572,10 +9561,11 @@ Expression *PostExp::semantic(Scope *sc)
             return new ErrorExp();
         }
 
-        e1 = e1->modifiableLvalue(sc, e1);
+        if (e1->op != TOKarraylength)
+            e1 = e1->modifiableLvalue(sc, e1);
 
         Type *t1 = e1->type->toBasetype();
-        if (t1->ty == Tclass || t1->ty == Tstruct)
+        if (t1->ty == Tclass || t1->ty == Tstruct || e1->op == TOKarraylength)
         {   /* Check for operator overloading,
              * but rewrite in terms of ++e instead of e++
              */
@@ -9583,7 +9573,7 @@ Expression *PostExp::semantic(Scope *sc)
             /* If e1 is not trivial, take a reference to it
              */
             Expression *de = NULL;
-            if (e1->op != TOKvar)
+            if (e1->op != TOKvar && e1->op != TOKarraylength)
             {
                 // ref v = e1;
                 Identifier *id = Lexer::uniqueId("__postref");
diff --git a/src/interpret.c b/src/interpret.c
index fffd868d78a7..6ab1a97bcd8e 100644
--- a/src/interpret.c
+++ b/src/interpret.c
@@ -27,7 +27,6 @@
 #include "attrib.h" // for AttribDeclaration
 
 #include "template.h"
-TemplateInstance *isSpeculativeFunction(FuncDeclaration *fd);
 
 
 #define LOG     0
@@ -480,7 +479,7 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
          */
         int olderrors = global.errors;
         int oldgag = global.gag;
-        TemplateInstance *spec = isSpeculativeFunction(this);
+        TemplateInstance *spec = isSpeculative();
         if (global.gag && !spec)
             global.gag = 0;
         semantic3(scope);
diff --git a/src/mars.c b/src/mars.c
index c30d5f95197a..6a6dc183eb3a 100644
--- a/src/mars.c
+++ b/src/mars.c
@@ -117,6 +117,11 @@ bool Global::endGagging(unsigned oldGagged)
     return anyErrs;
 }
 
+bool Global::isSpeculativeGagging()
+{
+    return gag && gag == speculativeGag;
+}
+
 
 char *Loc::toChars()
 {
diff --git a/src/mars.h b/src/mars.h
index 24cd00b25267..9a35b3260189 100644
--- a/src/mars.h
+++ b/src/mars.h
@@ -262,6 +262,12 @@ struct Global
     unsigned gag;          // !=0 means gag reporting of errors & warnings
     unsigned gaggedErrors; // number of errors reported while gagged
 
+    /* Gagging can either be speculative (is(typeof()), etc)
+     * or because of forward references
+     */
+    unsigned speculativeGag; // == gag means gagging is for is(typeof);
+    bool isSpeculativeGagging();
+
     // Start gagging. Return the current number of gagged errors
     unsigned startGagging();
 
diff --git a/src/mtype.c b/src/mtype.c
index 694650351c43..e8f1b69cf227 100644
--- a/src/mtype.c
+++ b/src/mtype.c
@@ -6730,7 +6730,12 @@ Type *TypeTypeof::semantic(Loc loc, Scope *sc)
         Scope *sc2 = sc->push();
         sc2->intypeof++;
         sc2->flags |= sc->flags & SCOPEstaticif;
+        unsigned oldspecgag = global.speculativeGag;
+        if (global.gag)
+            global.speculativeGag = global.gag;
         exp = exp->semantic(sc2);
+        global.speculativeGag = oldspecgag;
+
 #if DMDV2
         if (exp->type && exp->type->ty == Tfunction &&
             ((TypeFunction *)exp->type)->isproperty)
diff --git a/src/struct.c b/src/struct.c
index e13f3a9b82f3..0edec4de4ac1 100644
--- a/src/struct.c
+++ b/src/struct.c
@@ -473,7 +473,12 @@ void StructDeclaration::semantic(Scope *sc)
             if (sizeok == 0 && s->isAliasDeclaration())
                 finalizeSize();
         }
+        // Ungag errors when not speculative
+        unsigned oldgag = global.gag;
+        if (global.isSpeculativeGagging() && !isSpeculative())
+            global.gag = 0;
         s->semantic(sc2);
+        global.gag = oldgag;
     }
 
     if (sizeok == 2)
diff --git a/src/traits.c b/src/traits.c
index ad676004fa13..707de874a098 100644
--- a/src/traits.c
+++ b/src/traits.c
@@ -451,6 +451,8 @@ Expression *TraitsExp::semantic(Scope *sc)
             Expression *e;
 
             unsigned errors = global.startGagging();
+            unsigned oldspec = global.speculativeGag;
+            global.speculativeGag = global.gag;
 
             Type *t = isType(o);
             if (t)
@@ -471,6 +473,7 @@ Expression *TraitsExp::semantic(Scope *sc)
                 }
             }
 
+            global.speculativeGag = oldspec;
             if (global.endGagging(errors))
             {
                 goto Lfalse;
diff --git a/test/fail_compilation/gag4269a.d b/test/fail_compilation/gag4269a.d
new file mode 100644
index 000000000000..23044710096e
--- /dev/null
+++ b/test/fail_compilation/gag4269a.d
@@ -0,0 +1,11 @@
+// REQUIRED_ARGS: -c -o-
+
+static if(is(typeof(A4269.sizeof))) {}
+
+class A4269
+{
+    void foo(B b);
+}
+
+
+ 
\ No newline at end of file
diff --git a/test/fail_compilation/gag4269b.d b/test/fail_compilation/gag4269b.d
new file mode 100644
index 000000000000..d8aad6365411
--- /dev/null
+++ b/test/fail_compilation/gag4269b.d
@@ -0,0 +1,6 @@
+// REQUIRED_ARGS: -c -o-
+
+static if(is(typeof(X2.init))) {}
+struct X2 { Y y; }
+
+ 
\ No newline at end of file
diff --git a/test/fail_compilation/gag4269c.d b/test/fail_compilation/gag4269c.d
new file mode 100644
index 000000000000..fe1e4fa05109
--- /dev/null
+++ b/test/fail_compilation/gag4269c.d
@@ -0,0 +1,5 @@
+// REQUIRED_ARGS: -c -o-
+
+static if(is(typeof(X3.init))) {}
+void X3(T3) { }
+ 
\ No newline at end of file
diff --git a/test/fail_compilation/gag4269d.d b/test/fail_compilation/gag4269d.d
new file mode 100644
index 000000000000..bba69ba391bb
--- /dev/null
+++ b/test/fail_compilation/gag4269d.d
@@ -0,0 +1,5 @@
+// REQUIRED_ARGS: -c -o-
+
+static if(is(typeof(X4.init))) {}
+Y4 X4() { return typeof(return).init; }
+ 
\ No newline at end of file
diff --git a/test/fail_compilation/gag4269e.d b/test/fail_compilation/gag4269e.d
new file mode 100644
index 000000000000..72f53a981437
--- /dev/null
+++ b/test/fail_compilation/gag4269e.d
@@ -0,0 +1,4 @@
+// REQUIRED_ARGS: -c -o-
+
+static if(is(typeof(X8.init))) {}
+class X8 : Y8 {} 
\ No newline at end of file
diff --git a/test/fail_compilation/gag4269f.d b/test/fail_compilation/gag4269f.d
new file mode 100644
index 000000000000..857cdd18f88f
--- /dev/null
+++ b/test/fail_compilation/gag4269f.d
@@ -0,0 +1,4 @@
+// REQUIRED_ARGS: -c -o-
+
+static if(is(typeof(X9.init))) {}
+interface X9 { Y9 y; }
\ No newline at end of file
diff --git a/test/runnable/xtest46.d b/test/runnable/xtest46.d
index 3522f95af813..e524b0578245 100644
--- a/test/runnable/xtest46.d
+++ b/test/runnable/xtest46.d
@@ -1120,6 +1120,17 @@ void test62()
 
 /***************************************************/
 
+void test3927()
+{
+    int[] array;
+    assert(array.length++ == 0);
+    assert(array.length == 1);
+    assert(array.length-- == 1);
+    assert(array.length == 0);
+}
+
+/***************************************************/
+
 void test63()
 {
     int[3] b;
@@ -4771,7 +4782,7 @@ int main()
     test103();
     test104();
     test105();
-
+    test3927();
     test107();
 
     test109();