Fixes to block scalars and yamlTestSuite

* Properly handle empty block scalars and trailing lines
 * Fixed a bug in yamlTestSuite that led to lots of open file handles

private/fastparse.nim

@@ -844,6 +844,8 @@ template blockScalar(lexer: BaseLexer, content: var string,
     chomp: ChompType = ctClip
     detectedIndent = false
     recentLineMoreIndented = false
+  let parentIndent = if ancestry.len > 0:
+          ancestry[ancestry.high].indentation else: 0
   
   case lexer.buf[lexer.bufpos]
   of '|': literal = true
@@ -877,8 +879,6 @@ template blockScalar(lexer: BaseLexer, content: var string,
         # TODO: is this correct?
   else: assert(false)
   var newlines = 0
-  let parentIndent = if ancestry.len > 0:
-          ancestry[ancestry.high].indentation else: 0
   content = ""
   block outer:
     while true:
@@ -947,6 +947,10 @@ template blockScalar(lexer: BaseLexer, content: var string,
               break outer
             else:
               blockIndent = lexer.getColNumber(lexer.bufpos) - parentIndent
+              if blockIndent == 0:
+                stateAfter = if blockIndent + parentIndent > 0:
+                    fpBlockObjectStart else: fpBlockLineStart
+                break outer
               detectedIndent = true
               break
             lexer.bufpos.inc()
@@ -964,7 +968,7 @@ template blockScalar(lexer: BaseLexer, content: var string,
           break outer
         of ' ', '\t':
           if not literal:
-            if not recentLineMoreIndented:
+            if content.len > 0:
               recentLineMoreIndented = true
               newlines.inc()
         else:
@@ -974,7 +978,11 @@ template blockScalar(lexer: BaseLexer, content: var string,
               newlines.inc()
         if newlines > 0:
           if literal: content.add(repeat('\l', newlines))
-          elif newlines == 1: content.add(' ')
+          elif newlines == 1:
+            if content.len == 0: content.add('\l')
+            else: content.add(' ')
+          else:
+            if content.len == 0: content.add(repeat('\l', newlines))
             else: content.add(repeat('\l', newlines - 1))
           newlines = 0
         while true:
@@ -994,8 +1002,11 @@ template blockScalar(lexer: BaseLexer, content: var string,
           else: content.add(c)
           lexer.bufpos.inc()
   case chomp
-  of ctClip: content.add('\l')
-  of ctKeep: content.add(repeat('\l', newlines))
+  of ctClip:
+    if content.len > 0: content.add('\l')
+  of ctKeep: 
+    if content.len > 0: content.add(repeat('\l', newlines))
+    else: content.add(repeat('\l', newlines - 1))
   of ctStrip: discard
   debug("lex: \"" & content & '\"')
 
@@ -1158,8 +1169,8 @@ proc parse*(p: YamlParser, s: Stream): YamlStream =
               p.lexer.plainScalar(content, cBlock)
               state = fpBlockAfterPlainScalar
         of ' ':
-          let c = p.lexer.buf[p.lexer.bufpos]
           p.lexer.skipIndentation()
+          let c = p.lexer.buf[p.lexer.bufpos]
           if c in {'\l', '\c', '#', EndOfFile}:
             p.lexer.lineEnding()
             handleLineEnd(true)
@@ -1350,7 +1361,8 @@ proc parse*(p: YamlParser, s: Stream): YamlStream =
           if tag == yTagQuestionMark: tag = yTagExclamationMark
           yield scalarEvent(content, tag, anchor)
           handleObjectEnd(stateAfter)
-          if stateAfter == fpBlockObjectStart:
+          if stateAfter == fpBlockObjectStart and
+              p.lexer.buf[p.lexer.bufpos] != '#':
             indentation = p.lexer.getColNumber(p.lexer.bufpos)
             closeMoreIndentedLevels()
         of '-':

test/yamlTestSuite.nim

@@ -31,9 +31,10 @@ for kind, dirPath in walkDir("yaml-dev-kit"):
             var
                 tagLib = initExtendedTagLibrary()
                 parser = newYamlParser(tagLib)
-                actual = parser.parse(newFileStream(dirPath / "in.yaml"))
-                expected = parseEventStream(
-                        newFileStream(dirPath / "test.event"), tagLib)
+                actualIn = newFileStream(dirPath / "in.yaml")
+                actual = parser.parse(actualIn)
+                expectedIn = newFileStream(dirPath / "test.event")
+                expected = parseEventStream(expectedIn, tagLib)
             styledWriteLine(stdout, fgBlue, "[test] ", fgWhite, dirPath[^4..^1],
                             ": ", strip(readFile(dirPath / "===")), resetStyle)
             try:
@@ -45,6 +46,8 @@ for kind, dirPath in walkDir("yaml-dev-kit"):
                                   ": Expected stream end, got " &
                                   $actualEvent.kind)
                         gotErrors = true
+                        actualIn.close()
+                        expectedIn.close()
                         break curTest
                     let expectedEvent = expected.next()
                     if expectedEvent != actualEvent:
@@ -52,6 +55,8 @@ for kind, dirPath in walkDir("yaml-dev-kit"):
                         echoError("At token #" & $i &
                                 ": Actual tokens do not match expected tokens")
                         gotErrors = true
+                        actualIn.close()
+                        expectedIn.close()
                         break curTest
                     i.inc()
                 if not expected.finished():
@@ -68,6 +73,8 @@ for kind, dirPath in walkDir("yaml-dev-kit"):
                          pe.msg
                     echo pe.lineContent
                 else: echo e.msg
+            actualIn.close()
+            expectedIn.close()
 
 if gotErrors:
     echoError("There were errors while running the tests")