From 02cc7931ef0f04218bd50b3e0e396a6dcb009962 Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Tue, 19 May 2015 17:14:28 +0200
Subject: epub: Parse CSS combinators left-associatively.

Fixes bug 695994 where multiple child selectors would not match properly.

The "a > b > c" rule should be interpreted as ((a > b) > c) in order
to match properly.
---
 source/html/css-parse.c | 67 ++++++++++++++++++++-----------------------------
 1 file changed, 27 insertions(+), 40 deletions(-)

(limited to 'source/html')

diff --git a/source/html/css-parse.c b/source/html/css-parse.c
index 0946043e..f9d7595c 100644
--- a/source/html/css-parse.c
+++ b/source/html/css-parse.c
@@ -776,55 +776,42 @@ static fz_css_selector *parse_simple_selector(struct lexbuf *buf)
 	fz_css_error(buf, "expected selector");
 }
 
-static fz_css_selector *parse_combinator(struct lexbuf *buf, fz_css_selector *a)
+static fz_css_selector *parse_combinator(struct lexbuf *buf, int c, fz_css_selector *a)
 {
-	fz_css_selector *s, *b;
-	if (accept(buf, '+'))
-	{
-		white(buf);
-		b = parse_selector(buf);
-		s = fz_new_css_selector(buf->ctx, NULL);
-		s->combine = '+';
-		s->left = a;
-		s->right = b;
-		return s;
-	}
-	if (accept(buf, '>'))
-	{
-		white(buf);
-		b = parse_selector(buf);
-		s = fz_new_css_selector(buf->ctx, NULL);
-		s->combine = '>';
-		s->left = a;
-		s->right = b;
-		return s;
-	}
-	return a;
+	fz_css_selector *sel, *b;
+	white(buf);
+	b = parse_simple_selector(buf);
+	sel = fz_new_css_selector(buf->ctx, NULL);
+	sel->combine = c;
+	sel->left = a;
+	sel->right = b;
+	return sel;
 }
 
 static fz_css_selector *parse_selector(struct lexbuf *buf)
 {
-	fz_css_selector *s, *a, *b;
-
-	a = parse_simple_selector(buf);
-	if (accept(buf, ' '))
+	fz_css_selector *sel = parse_simple_selector(buf);
+	for (;;)
 	{
-		s = parse_combinator(buf, a);
-		if (s == a && buf->lookahead != ',' && buf->lookahead != '{' && buf->lookahead != EOF)
+		if (accept(buf, ' '))
 		{
-			b = parse_selector(buf);
-			s = fz_new_css_selector(buf->ctx, NULL);
-			s->combine = ' ';
-			s->left = a;
-			s->right = b;
-			return s;
+			if (accept(buf, '+'))
+				sel = parse_combinator(buf, '+', sel);
+			else if (accept(buf, '>'))
+				sel = parse_combinator(buf, '>', sel);
+			else if (buf->lookahead != ',' && buf->lookahead != '{' && buf->lookahead != EOF)
+				sel = parse_combinator(buf, ' ', sel);
+			else
+				break;
 		}
+		else if (accept(buf, '+'))
+			sel = parse_combinator(buf, '+', sel);
+		else if (accept(buf, '>'))
+			sel = parse_combinator(buf, '>', sel);
+		else
+			break;
 	}
-	else
-	{
-		s = parse_combinator(buf, a);
-	}
-	return s;
+	return sel;
 }
 
 static fz_css_selector *parse_selector_list(struct lexbuf *buf)
-- 
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