Fixed small bugs

* allow '!' at beginning of tag URI in %TAG directive
 * recognise \t as start of more indented line in block flow scalar
 * Made testEventParser more robust

private/fastparse.nim

@@ -492,6 +492,10 @@ template tagUri(lexer: BaseLexer, uri: var string) =
   while lexer.buf[lexer.bufpos] in space:
     lexer.bufpos.inc()
   var c = lexer.buf[lexer.bufpos]
+  if c == '!':
+    uri.add(c)
+    lexer.bufpos.inc()
+    c = lexer.buf[lexer.bufpos]
   while c notin spaceOrLineEnd:
     case c
     of 'a' .. 'z', 'A' .. 'Z', '0' .. '9', '#', ';', '/', '?', ':', '@', '&',
@@ -964,7 +968,7 @@ template blockScalar(lexer: BaseLexer, content: var string,
         of EndOfFile:
           stateAfter = fpBlockLineStart
           break outer
-        of ' ':
+        of ' ', '\t':
           if not literal:
             if not recentLineMoreIndented:
               recentLineMoreIndented = true

test/testEventParser.nim

@@ -63,6 +63,8 @@ proc nextToken(lex: var EventLexer): LexerToken =
         while lex.buf[lex.bufpos] != '>':
             lex.content.add(lex.buf[lex.bufpos])
             lex.bufpos.inc()
+            if lex.buf[lex.bufpos] == EndOfFile:
+                raise newException(EventStreamError, "Unclosed tag URI!")
         result = chevTag
         lex.bufpos.inc()
     of '&':