From e3650c7495c1b94900bf3ab09895c5ea5a4aea98 Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Fri, 15 Feb 2019 17:12:48 +0100
Subject: [PATCH 1/3] Fix #5004: Turn assertion into test

---
 compiler/src/dotty/tools/dotc/core/Contexts.scala      | 1 -
 compiler/src/dotty/tools/dotc/typer/Applications.scala | 3 ++-
 tests/neg/i5004.scala                                  | 6 ++++++
 3 files changed, 8 insertions(+), 2 deletions(-)
 create mode 100644 tests/neg/i5004.scala

diff --git a/compiler/src/dotty/tools/dotc/core/Contexts.scala b/compiler/src/dotty/tools/dotc/core/Contexts.scala
index 842132270615..9fb22b758f75 100644
--- a/compiler/src/dotty/tools/dotc/core/Contexts.scala
+++ b/compiler/src/dotty/tools/dotc/core/Contexts.scala
@@ -378,7 +378,6 @@ object Contexts {
      *   - as scope: The parameters of the auxiliary constructor.
      */
     def thisCallArgContext: Context = {
-      assert(owner.isClassConstructor)
       val constrCtx = outersIterator.dropWhile(_.outer.owner == owner).next()
       superOrThisCallContext(owner, constrCtx.scope)
         .setTyperState(typerState)
diff --git a/compiler/src/dotty/tools/dotc/typer/Applications.scala b/compiler/src/dotty/tools/dotc/typer/Applications.scala
index 5f3449a89080..460a9c21a8b5 100644
--- a/compiler/src/dotty/tools/dotc/typer/Applications.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Applications.scala
@@ -747,7 +747,8 @@ trait Applications extends Compatibility { self: Typer with Dynamic =>
    *  otherwise the current context.
    */
   def argCtx(app: untpd.Tree)(implicit ctx: Context): Context =
-    if (untpd.isSelfConstrCall(app)) ctx.thisCallArgContext else ctx
+    if (ctx.owner.isClassConstructor && untpd.isSelfConstrCall(app)) ctx.thisCallArgContext
+    else ctx
 
   /** Typecheck application. Result could be an `Apply` node,
    *  or, if application is an operator assignment, also an `Assign` or
diff --git a/tests/neg/i5004.scala b/tests/neg/i5004.scala
new file mode 100644
index 000000000000..16532bbec69e
--- /dev/null
+++ b/tests/neg/i5004.scala
@@ -0,0 +1,6 @@
+object i0 {
+1 match {
+def this(): Int  // error // error
+  def this()     // error
+}                // error
+}
\ No newline at end of file

From c496db782912eb405d177a7744f6ecad0b16bafc Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Fri, 15 Feb 2019 17:32:43 +0100
Subject: [PATCH 2/3] Exempt combinations of Java fields and methods as double
 defs

Exempt combinations of Java fields and methods from being flagged
as double definitions.

Java fields don't get a getter, so the pattern

    int f
    int f() = f

is OK (and quite common).
---
 compiler/src/dotty/tools/dotc/typer/Checking.scala | 5 ++++-
 tests/pos/i4739.java                               | 6 ++++++
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 tests/pos/i4739.java

diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala
index 814459a672d6..226d40b6f875 100644
--- a/compiler/src/dotty/tools/dotc/typer/Checking.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Checking.scala
@@ -744,7 +744,10 @@ trait Checking {
     def checkDecl(decl: Symbol): Unit = {
       for (other <- seen(decl.name)) {
         typr.println(i"conflict? $decl $other")
-        if (decl.matches(other)) {
+        def javaFieldMethodPair =
+          decl.is(JavaDefined) && other.is(JavaDefined) &&
+          decl.is(Method) != other.is(Method)
+        if (decl.matches(other) && !javaFieldMethodPair) {
           def doubleDefError(decl: Symbol, other: Symbol): Unit =
             if (!decl.info.isErroneous && !other.info.isErroneous)
               ctx.error(DoubleDeclaration(decl, other), decl.sourcePos)
diff --git a/tests/pos/i4739.java b/tests/pos/i4739.java
new file mode 100644
index 000000000000..a959eec4e2d1
--- /dev/null
+++ b/tests/pos/i4739.java
@@ -0,0 +1,6 @@
+public class TestJava {
+  int foo;
+  int foo() {
+    return this.foo;
+  }
+}
\ No newline at end of file

From 5e9f086eaa13b53337659dbc10b6344f267976bc Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Fri, 15 Feb 2019 19:00:54 +0100
Subject: [PATCH 3/3] Fix test

---
 tests/pos/i4739.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/pos/i4739.java b/tests/pos/i4739.java
index a959eec4e2d1..6daa9ff113d5 100644
--- a/tests/pos/i4739.java
+++ b/tests/pos/i4739.java
@@ -1,4 +1,4 @@
-public class TestJava {
+public class i4739 {
   int foo;
   int foo() {
     return this.foo;