Ref sbt#520

This is an improvement over the status quo of forked Javac error parsing,
but likely not a complete fix.

"Normal" Java error messages look like:

```
/path/a.java:100:1: error message
        if (x.isBar) {
              ^
  symbol: xxx
  location: xxx
```

However, under certain circumstances javac reports compiler errors are reported as:

```
/path/a.java:100:1: error message
symbol: xxx
location: xxx
if (x.isBar) {
```

Current parsing assumes existence of `^` as well as indentation before "symbol" etc.

Ultimately a better way of handling forking probably is to define our own small commandline app, like forked tests are done.

internal/zinc-compile-core/src/main/scala/sbt/internal/inc/javac/JavaErrorParser.scala

@@ -83,6 +83,33 @@ class JavaErrorParser(relativeDir: File = new File(new File(".").getAbsolutePath
     }) ^^ {
       case xs => xs.mkString("\n")
     }
+  val nonPathLine: Parser[String] = {
+    val nonPathLine0 = new Parser[String] {
+      def isStopChar(c: Char): Boolean = c == '\n' || c == '\r'
+
+      def apply(in: Input) = {
+        val source = in.source
+        val offset = in.offset
+        var i = offset
+        while (i < source.length && !isStopChar(source.charAt(i))) {
+          i += 1
+        }
+        val line = source.subSequence(offset, i).toString
+        if ((line.startsWith("/") || line.contains("\\")) && line.contains(".java"))
+          Failure("Path found", in)
+        else if (i == offset) Failure("Empty", in)
+        else Success(line, in.drop(i - offset))
+      }
+    }
+    nonPathLine0 ~ """[\r]?[\n]?""".r ^^ {
+      case msg ~ endline => msg + endline
+    }
+  }
+  val nonPathLines: Parser[String] = {
+    rep(nonPathLine) ^^ {
+      case lines => lines.mkString("")
+    }
+  }
 
   // Parses ALL characters until an expected character is met.
   def allUntilChar(c: Char): Parser[String] = allUntilChars(Array(c))
@@ -148,15 +175,21 @@ class JavaErrorParser(relativeDir: File = new File(new File(".").getAbsolutePath
     val fileLineMessage = fileAndLineNo ~ SEMICOLON ~ restOfLine ^^ {
       case (file, line) ~ _ ~ msg => (file, line, msg)
     }
-    fileLineMessage ~ allUntilCaret ~ restOfLine ~ (allIndented.?) ^^ {
-      case (file, line, msg) ~ contents ~ r ~ ind =>
+    fileLineMessage ~ (allUntilCaret ~ '^' ~ restOfLine).? ~ (nonPathLines.?) ^^ {
+      case (file, line, msg) ~ contentsOpt ~ ind =>
         new JavaProblem(
           new JavaPosition(
             findFileSource(file),
             line,
-            contents + '^' + r + ind
+            (contentsOpt match {
+              case Some(contents ~ _ ~ r) => contents + '^' + r
+              case _                      => ""
+            }) + ind
               .getOrElse(""), // TODO - Actually parse caret position out of here.
-            getOffset(contents)
+            (contentsOpt match {
+              case Some(contents ~ _ ~ _) => getOffset(contents)
+              case _                      => 0
+            })
           ),
           Severity.Error,
           msg
@@ -169,14 +202,20 @@ class JavaErrorParser(relativeDir: File = new File(new File(".").getAbsolutePath
     val fileLineMessage = fileAndLineNo ~ SEMICOLON ~ WARNING ~ SEMICOLON ~ restOfLine ^^ {
       case (file, line) ~ _ ~ _ ~ _ ~ msg => (file, line, msg)
     }
-    fileLineMessage ~ allUntilCaret ~ restOfLine ~ (allIndented.?) ^^ {
-      case (file, line, msg) ~ contents ~ r ~ ind =>
+    fileLineMessage ~ (allUntilCaret ~ '^' ~ restOfLine).? ~ (nonPathLines.?) ^^ {
+      case (file, line, msg) ~ contentsOpt ~ ind =>
         new JavaProblem(
           new JavaPosition(
             findFileSource(file),
             line,
-            contents + "^" + r + ind.getOrElse(""),
-            getOffset(contents)
+            (contentsOpt match {
+              case Some(contents ~ _ ~ r) => contents + '^' + r
+              case _                      => ""
+            }) + ind.getOrElse(""),
+            (contentsOpt match {
+              case Some(contents ~ _ ~ _) => getOffset(contents)
+              case _                      => 0
+            })
           ),
           Severity.Warn,
           msg
@@ -201,9 +240,15 @@ class JavaErrorParser(relativeDir: File = new File(new File(".").getAbsolutePath
         )
     }
 
+  val outputSumamry: Parser[Unit] =
+    """(\s*)(\d+) (\w+)""".r ~ restOfLine ^^ {
+      case a ~ b =>
+        ()
+    }
+
   val potentialProblem: Parser[Problem] = warningMessage | errorMessage | noteMessage | javacError
 
-  val javacOutput: Parser[Seq[Problem]] = rep(potentialProblem)
+  val javacOutput: Parser[Seq[Problem]] = rep(potentialProblem) <~ opt(outputSumamry)
 
   /**
    * Example:

internal/zinc-compile-core/src/test/scala/sbt/internal/inc/javac/javaErrorParserSpec.scala

@@ -3,33 +3,35 @@ package internal
 package inc
 package javac
 
+import org.scalatest.DiagrammedAssertions
 import sbt.util.Logger
+import sbt.internal.util.ConsoleLogger
 
-class JavaErrorParserSpec extends UnitSpec {
+class JavaErrorParserSpec extends UnitSpec with DiagrammedAssertions {
 
-  "The JavaErrorParser" should "be able to parse linux errors" in parseSampleLinux()
+  "The JavaErrorParser" should "be able to parse Linux errors" in parseSampleLinux()
   it should "be able to parse windows file names" in parseWindowsFile()
   it should "be able to parse windows errors" in parseSampleWindows()
   it should "be able to parse javac errors" in parseSampleJavac()
   it should "register the position of errors" in parseErrorPosition()
   it should "be able to parse multiple errors" in parseMultipleErrors()
+  it should "be able to parse multiple errors without carrets or indentation" in parseMultipleErrors2()
 
   def parseSampleLinux() = {
     val parser = new JavaErrorParser()
-    val logger = Logger.Null
+    val logger = ConsoleLogger()
     val problems = parser.parseProblems(sampleLinuxMessage, logger)
 
-    problems should have size (1)
-    problems(0).position.sourcePath.get shouldBe ("/home/me/projects/sample/src/main/Test.java")
-
+    assert(problems.size == 1)
+    assert(problems(0).position.sourcePath.get == ("/home/me/projects/sample/src/main/Test.java"))
   }
 
   def parseSampleWindows() = {
     val parser = new JavaErrorParser()
-    val logger = Logger.Null
+    val logger = ConsoleLogger()
     val problems = parser.parseProblems(sampleWindowsMessage, logger)
 
-    problems should have size (1)
+    assert(problems.size == 1)
     problems(0).position.sourcePath.get shouldBe (windowsFile)
 
   }
@@ -47,35 +49,62 @@ class JavaErrorParserSpec extends UnitSpec {
 
   def parseSampleJavac() = {
     val parser = new JavaErrorParser()
-    val logger = Logger.Null
+    val logger = ConsoleLogger()
     val problems = parser.parseProblems(sampleJavacMessage, logger)
-    problems should have size (1)
+    assert(problems.size == 1)
     problems(0).message shouldBe (sampleJavacMessage)
   }
 
   def parseErrorPosition() = {
     val parser = new JavaErrorParser()
-    val logger = Logger.Null
+    val logger = ConsoleLogger()
     val problems = parser.parseProblems(sampleErrorPosition, logger)
-    problems should have size (1)
+    assert(problems.size == 1)
     problems(0).position.offset.isPresent shouldBe true
     problems(0).position.offset.get shouldBe 23
   }
 
   def parseMultipleErrors() = {
     val parser = new JavaErrorParser()
-    val logger = Logger.Null
+    val logger = ConsoleLogger()
     val problems = parser.parseProblems(sampleMultipleErrors, logger)
-    problems should have size (5)
+    assert(problems.size == 5)
+  }
+
+  def parseMultipleErrors2() = {
+    val parser = new JavaErrorParser()
+    val logger = ConsoleLogger()
+    val problems = parser.parseProblems(sampleLinuxMessage2, logger)
+
+    assert(problems.size == 3)
+    assert(problems(0).position.sourcePath.get == ("/home/me/projects/sample/src/main/Test.java"))
   }
 
   def sampleLinuxMessage =
     """
-      |/home/me/projects/sample/src/main/Test.java:4: cannot find symbol
-      |symbol  : method baz()
-      |location: class Foo
-      |return baz();
-    """.stripMargin
+      |/home/me/projects/sample/src/main/Test.java:18: error: cannot find symbol
+      |          baz();
+      |          ^
+      |  symbol:   method baz()
+      |  location: class AbstractActorRef
+      |1 error.
+      |""".stripMargin
+
+  def sampleLinuxMessage2 =
+    """
+      |/home/me/projects/sample/src/main/Test.java:100:1: cannot find symbol
+      |symbol: method isBar()
+      |location: variable x of type com.example.List
+      |if (x.isBar()) {
+      |/home/me/projects/sample/src/main/Test.java:200:1: cannot find symbol
+      |symbol: method isBar()
+      |location: variable x of type com.example.List
+      |} else if (x.isBar()) {
+      |/home/me/projects/sample/src/main/Test.java:300:1: cannot find symbol
+      |symbol: method isBar()
+      |location: variable x of type com.example.List
+      |foo.baz(runtime, x.isBar());
+      |""".stripMargin
 
   def sampleWindowsMessage =
     s"""
@@ -117,5 +146,6 @@ class JavaErrorParserSpec extends UnitSpec {
        |/home/foo/sbt/internal/inc/javac/test1.java:7: warning: [deprecation] RMISecurityException(String) in RMISecurityException has been deprecated
        |        throw new RMISecurityException("O NOES");
        |              ^
+       |5 errors.
        |""".stripMargin
 }