SI-7376 Unmoored doc has correct position

The unmoored DocComment is created more eagerly so that its position
is correct despite subsequent line comments. (Previously, skipComment
would advance docPos.)

It looks like the error caret is still off by one when a doc comment
shows up in the middle of an operator, and who doesn't scaladoc the
interior of expressions?

Another bug fixed by Paul's refactor is that additional comments
between the doc and the entity no longer breaks the scaladoc.
Test added.

3 files changed, 61 insertions, 25 deletions

diff --git a/src/scaladoc/scala/tools/nsc/doc/ScaladocAnalyzer.scala b/src/scaladoc/scala/tools/nsc/doc/ScaladocAnalyzer.scala
index 99a6ab9e3e..003c439f65 100644
--- a/src/scaladoc/scala/tools/nsc/doc/ScaladocAnalyzer.scala
+++ b/src/scaladoc/scala/tools/nsc/doc/ScaladocAnalyzer.scala
@@ -149,9 +149,9 @@ abstract class ScaladocSyntaxAnalyzer[G <: Global](val global: G) extends Syntax
 
   class ScaladocUnitScanner(unit0: CompilationUnit, patches0: List[BracePatch]) extends UnitScanner(unit0, patches0) {
 
-    private var docBuffer: StringBuilder = null        // buffer for comments
-    private var docPos: Position         = NoPosition  // last doc comment position
-    private var inDocComment             = false
+    private var docBuffer: StringBuilder = null        // buffer for comments (non-null while scanning)
+    private var inDocComment             = false       // if buffer contains double-star doc comment
+    private var lastDoc: DocComment      = null        // last comment if it was double-star doc 
 
     private lazy val unmooredParser = {                // minimalist comment parser
       import scala.tools.nsc.doc.base.{comment => _, _}
@@ -180,7 +180,7 @@ abstract class ScaladocSyntaxAnalyzer[G <: Global](val global: G) extends Syntax
      * Also warn under -Xlint, but otherwise only warn in the presence of suspicious
      * tags that appear to be documenting API.  Warnings are suppressed while parsing
      * the local comment so that comments of the form `[at] Martin` will not trigger a warning.
-     * In addition, tags for `todo`, `note` and `example` are ignored.
+     * By omission, tags for `see`, `todo`, `note` and `example` are ignored.
      */
     override def discardDocBuffer() = {
       import scala.tools.nsc.doc.base.comment.Comment
@@ -193,13 +193,10 @@ abstract class ScaladocSyntaxAnalyzer[G <: Global](val global: G) extends Syntax
       }
       def isDirty = unclean(unmooredParser parseComment doc)
       if ((doc ne null) && (settings.lint || isDirty))
-        unit.warning(docPos, "discarding unmoored doc comment")
+        unit.warning(doc.pos, "discarding unmoored doc comment")
     }
 
-    override def flushDoc(): DocComment = {
-      if (docBuffer eq null) null
-      else try DocComment(docBuffer.toString, docPos) finally docBuffer = null
-    }
+    override def flushDoc(): DocComment = (try lastDoc finally lastDoc = null)
 
     override protected def putCommentChar() {
       if (inDocComment)
@@ -218,23 +215,19 @@ abstract class ScaladocSyntaxAnalyzer[G <: Global](val global: G) extends Syntax
       super.skipBlockComment()
     }
     override def skipComment(): Boolean = {
-      super.skipComment() && {
-        if (docBuffer ne null) {
-          if (inDocComment)
-            foundDocComment(docBuffer.toString, offset, charOffset - 2)
-          else
-            try foundComment(docBuffer.toString, offset, charOffset - 2) finally docBuffer = null
-        }
+      // emit a block comment; if it's double-star, make Doc at this pos
+      def foundStarComment(start: Int, end: Int) = try {
+        val str = docBuffer.toString
+        val pos = new RangePosition(unit.source, start, start, end)
+        unit.comment(pos, str)
+        if (inDocComment)
+          lastDoc = DocComment(str, pos)
         true
+      } finally {
+        docBuffer    = null
+        inDocComment = false
       }
-    }
-    def foundComment(value: String, start: Int, end: Int) {
-      val pos = new RangePosition(unit.source, start, start, end)
-      unit.comment(pos, value)
-    }
-    def foundDocComment(value: String, start: Int, end: Int) {
-      docPos = new RangePosition(unit.source, start, start, end)
-      unit.comment(docPos, value)
+      super.skipComment() && ((docBuffer eq null) || foundStarComment(offset, charOffset - 2))
     }
   }
   class ScaladocUnitParser(unit: CompilationUnit, patches: List[BracePatch]) extends UnitParser(unit, patches) {
diff --git a/test/scaladoc/run/t5527.check b/test/scaladoc/run/t5527.check
index 54595652cd..235e73b5c8 100644
--- a/test/scaladoc/run/t5527.check
+++ b/test/scaladoc/run/t5527.check
@@ -1,6 +1,12 @@
 newSource1:47: warning: discarding unmoored doc comment
         /** Document this crucial constant for posterity.
         ^
+newSource1:64: warning: discarding unmoored doc comment
+        /*************************\
+        ^
+newSource1:73: warning: discarding unmoored doc comment
+        val i = 10 */** Important!
+                   ^
 [[syntax trees at end of                    parser]] // newSource1
 package <empty> {
   object UselessComments extends scala.AnyRef {
@@ -54,6 +60,14 @@ package <empty> {
     def test7 = {
       val u = 4;
       0.to(u).foreach(((i) => println(i)))
+    };
+    def test8 = {
+      val z = "fancy";
+      z.replace("fanc", "arts")
+    };
+    def test9 = {
+      val i = 10.$times(10);
+      assert(i.$eq$eq(100))
     }
   };
   /** comments that we should keep */
@@ -108,7 +122,11 @@ package <empty> {
         super.<init>();
         ()
       }
-    }
+    };
+    /** Get the simple value.
+       *  @return the default value
+       */
+    def value: Int = 7
   }
 }
 
diff --git a/test/scaladoc/run/t5527.scala b/test/scaladoc/run/t5527.scala
index af0c1f8d36..60ae23c1a7 100644
--- a/test/scaladoc/run/t5527.scala
+++ b/test/scaladoc/run/t5527.scala
@@ -72,6 +72,24 @@ object Test extends DirectTest {
         for (i <- 0 to u)
           println(i)
       }
+      def test8 = {
+        /*************************\
+         * Fancy ASCII Art Block *
+         *   @author som-snytt   *
+        \*************************/
+        // this is just a local
+        val z = "fancy"
+        z replace ("fanc", "arts")
+      }
+      def test9 = {
+        val i = 10 */** Important!
+                     *  We have to multiply here!
+                     *  @author community
+                     *  @see SI-1234
+                     */
+                10
+        assert(i == 100)
+      }
     }
 
     /** comments that we should keep */
@@ -108,6 +126,13 @@ object Test extends DirectTest {
       /** class D */
       @deprecated("use ... instead", "2.10.0")
       class D
+
+      /** Get the simple value.
+       *  @return the default value
+       */
+      // an intervening line comment
+      /* I had more to say, but didn't want to pollute the scaladoc. */
+      def value: Int = 7
     }
   """.trim