Merge pull request scala#3951 from pawel-wiejacha/2.11.x_SI-8810_fix

scaladoc: fixed code block indentation normalization

Author: gkossakowski

src/scaladoc/scala/tools/nsc/doc/base/CommentFactoryBase.scala

@@ -723,49 +723,15 @@ trait CommentFactoryBase { this: MemberLookupBase =>
      */
     def normalizeIndentation(_code: String): String = {
 
-      val code = _code.trim
-      var maxSkip = Integer.MAX_VALUE
-      var crtSkip = 0
-      var wsArea = true
-      var index = 0
-      var firstLine = true
-      var emptyLine = true
-
-      while (index < code.length) {
-        code(index) match {
-          case ' ' =>
-            if (wsArea)
-              crtSkip += 1
-          case c =>
-            wsArea = (c == '\n')
-            maxSkip = if (firstLine || emptyLine) maxSkip else if (maxSkip <= crtSkip) maxSkip else crtSkip
-            crtSkip = if (c == '\n') 0 else crtSkip
-            firstLine = if (c == '\n') false else firstLine
-            emptyLine = if (c == '\n') true else false
-        }
-        index += 1
-      }
+      val code = _code.replaceAll("\\s+$", "").dropWhile(_ == '\n') // right-trim + remove all leading '\n'
+      val lines = code.split("\n")
 
-      if (maxSkip == 0)
-        code
-      else {
-        index = 0
-        val builder = new StringBuilder
-        while (index < code.length) {
-          builder.append(code(index))
-          if (code(index) == '\n') {
-            // we want to skip as many spaces are available, if there are less spaces (like on empty lines, do not
-            // over-consume them)
-            index += 1
-            val limit = index + maxSkip
-            while ((index < code.length) && (code(index) == ' ') && index < limit)
-              index += 1
-          }
-          else
-            index += 1
-        }
-        builder.toString
-      }
+      // maxSkip - size of the longest common whitespace prefix of non-empty lines
+      val nonEmptyLines = lines.filter(_.trim.nonEmpty)
+      val maxSkip = if (nonEmptyLines.isEmpty) 0 else nonEmptyLines.map(line => line.prefixLength(_ == ' ')).min
+
+      // remove common whitespace prefix
+      lines.map(line => if (line.trim.nonEmpty) line.substring(maxSkip) else line).mkString("\n")
     }
 
     def checkParaEnded(): Boolean = {

test/scaladoc/resources/code-indent.scala

@@ -20,6 +20,12 @@
  *       an alternative
  *         the e l s e branch
  *    }}}
+ *    {{{
+ *    Trait example {
+ *      Val x = a
+ *      Val y = b
+ *    }
+ *    }}}
  *    NB: Trailing spaces are necessary for this test!
  *    {{{
  *       l1

test/scaladoc/scalacheck/HtmlFactoryTest.scala

@@ -659,6 +659,7 @@ object Test extends Properties("HtmlFactory") {
         s.contains("<pre>two lines, one useful</pre>") &&
         s.contains("<pre>line1\nline2\nline3\nline4</pre>") &&
         s.contains("<pre>a ragged example\na (condition)\n  the t h e n branch\nan alternative\n  the e l s e branch</pre>") &&
+        s.contains("<pre>Trait example {\n  Val x = a\n  Val y = b\n}</pre>") &&
         s.contains("<pre>l1\n\nl2\n\nl3\n\nl4\n\nl5</pre>")
       }
       case _ => false
@@ -683,7 +684,7 @@ object Test extends Properties("HtmlFactory") {
     oneAuthor match {
       case node: scala.xml.Node => {
         val s = node.toString
-        s.contains("<h6>Author:</h6>")
+        s.contains("<h6>Author:</h6>") &&
         s.contains("<p>The Only Author\n</p>")
       }
       case _ => false
@@ -696,8 +697,8 @@ object Test extends Properties("HtmlFactory") {
     twoAuthors match {
       case node: scala.xml.Node => {
         val s = node.toString
-        s.contains("<h6>Authors:</h6>")
-        s.contains("<p>The First Author\n</p>")
+        s.contains("<h6>Authors:</h6>") &&
+        s.contains("<p>The First Author</p>") &&
         s.contains("<p>The Second Author\n</p>")
       }
       case _ => false