Remove unnecessary spaces at right side

parser/parser_test.go

@@ -440,6 +440,35 @@ a: |
 
    ccccccc
 d: eeeeeeeeeeeeeeeee
+`,
+		},
+		{
+			`
+a: b    
+  c
+`,
+			`
+a: b c
+`,
+		},
+		{
+			`
+a:    
+  b: c
+`,
+			`
+a:
+  b: c
+`,
+		},
+		{
+			`
+a: b    
+c: d
+`,
+			`
+a: b
+c: d
 `,
 		},
 	}

scanner/context.go

@@ -64,6 +64,17 @@ func (c *Context) addOriginBuf(r rune) {
 	c.obuf = append(c.obuf, r)
 }
 
+func (c *Context) removeRightSpaceFromBuf() int {
+	trimmedBuf := strings.TrimRight(string(c.obuf), " ")
+	buflen := len([]rune(trimmedBuf))
+	diff := len(c.obuf) - buflen
+	if diff > 0 {
+		c.obuf = c.obuf[:buflen]
+		c.buf = []rune(c.bufferedSrc())
+	}
+	return diff
+}
+
 func (c *Context) isDocument() bool {
 	return c.isLiteral || c.isFolded || c.isRawFolded
 }

scanner/scanner.go

@@ -296,6 +296,19 @@ func (s *Scanner) scanNewLine(ctx *Context, c rune) {
 		s.savedPos = s.pos()
 		s.savedPos.Column -= len([]rune(ctx.bufferedSrc()))
 	}
+
+	// if the following case, origin buffer has unnecessary two spaces.
+	// So, `removeRightSpaceFromOriginBuf` remove them, also fix column number too.
+	// ---
+	// a:[space][space]
+	//   b: c
+	removedNum := ctx.removeRightSpaceFromBuf()
+	if removedNum > 0 {
+		s.column -= removedNum
+		s.offset -= removedNum
+		s.savedPos.Column -= removedNum
+	}
+
 	if ctx.isEOS() {
 		s.addBufferedTokenIfExists(ctx)
 	} else if s.isAnchor {