Fix hang when parsing unclosed comment (#49)

google · Feb 8, 2025 · 2f27203 · 2f27203
2 parents 78bf4a5 + 96ebff4
commit 2f27203
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Showing 2 changed files with 15 additions and 9 deletions.
diff --git a/include/minja/minja.hpp b/include/minja/minja.hpp
@@ -1792,7 +1792,7 @@ class Parser {
         auto left = parseStringConcat();
         if (!left) throw std::runtime_error("Expected left side of 'logical compare' expression");
 
-        static std::regex compare_tok(R"(==|!=|<=?|>=?|in\b|is\b|not[\r\n\s]+in\b)");
+        static std::regex compare_tok(R"(==|!=|<=?|>=?|in\b|is\b|not\s+in\b)");
         static std::regex not_tok(R"(not\b)");
         std::string op_str;
         while (!(op_str = consumeToken(compare_tok)).empty()) {
@@ -2171,7 +2171,7 @@ class Parser {
     using TemplateTokenIterator = TemplateTokenVector::const_iterator;
 
     std::vector<std::string> parseVarNames() {
-      static std::regex varnames_regex(R"(((?:\w+)(?:[\r\n\s]*,[\r\n\s]*(?:\w+))*)[\r\n\s]*)");
+      static std::regex varnames_regex(R"(((?:\w+)(?:\s*,\s*(?:\w+))*)\s*)");
 
       std::vector<std::string> group;
       if ((group = consumeTokenGroups(varnames_regex)).empty()) throw std::runtime_error("Expected variable names");
@@ -2194,13 +2194,13 @@ class Parser {
     }
 
     TemplateTokenVector tokenize() {
-      static std::regex comment_tok(R"(\{#([-~]?)([\s\S\r\n]*?)([-~]?)#\})");
+      static std::regex comment_tok(R"(\{#([-~]?)([\s\S]*?)([-~]?)#\})");
       static std::regex expr_open_regex(R"(\{\{([-~])?)");
-      static std::regex block_open_regex(R"(^\{%([-~])?[\s\n\r]*)");
+      static std::regex block_open_regex(R"(^\{%([-~])?\s*)");
       static std::regex block_keyword_tok(R"((if|else|elif|endif|for|endfor|generation|endgeneration|set|endset|block|endblock|macro|endmacro|filter|endfilter|break|continue)\b)");
       static std::regex non_text_open_regex(R"(\{\{|\{%|\{#)");
-      static std::regex expr_close_regex(R"([\s\n\r]*([-~])?\}\})");
-      static std::regex block_close_regex(R"([\s\n\r]*([-~])?%\})");
+      static std::regex expr_close_regex(R"(\s*([-~])?\}\})");
+      static std::regex block_close_regex(R"(\s*([-~])?%\})");
 
       TemplateTokenVector tokens;
       std::vector<std::string> group;
@@ -2284,7 +2284,7 @@ class Parser {
               auto post_space = parseBlockClose();
               tokens.push_back(std::make_unique<EndGenerationTemplateToken>(location, pre_space, post_space));
             } else if (keyword == "set") {
-              static std::regex namespaced_var_regex(R"((\w+)[\s\n\r]*\.[\s\n\r]*(\w+))");
+              static std::regex namespaced_var_regex(R"((\w+)\s*\.\s*(\w+))");
 
               std::string ns;
               std::vector<std::string> var_names;
@@ -2336,6 +2336,11 @@ class Parser {
               throw std::runtime_error("Unexpected block: " + keyword);
             }
           } else if (std::regex_search(it, end, match, non_text_open_regex)) {
+            if (!match.position()) {
+                if (match[0] != "{#")
+                    throw std::runtime_error("Internal error: Expected a comment");
+                throw std::runtime_error("Missing end of comment tag");
+            }
             auto text_end = it + match.position();
             text = std::string(it, text_end);
             it = text_end;
@@ -2400,7 +2405,7 @@ class Parser {
 
               auto text = text_token->text;
               if (post_space == SpaceHandling::Strip) {
-                static std::regex trailing_space_regex(R"((\s|\r|\n)+$)");
+                static std::regex trailing_space_regex(R"(\s+$)");
                 text = std::regex_replace(text, trailing_space_regex, "");
               } else if (options.lstrip_blocks && it != end) {
                 auto i = text.size();
@@ -2410,7 +2415,7 @@ class Parser {
                 }
               }
               if (pre_space == SpaceHandling::Strip) {
-                static std::regex leading_space_regex(R"(^(\s|\r|\n)+)");
+                static std::regex leading_space_regex(R"(^\s+)");
                 text = std::regex_replace(text, leading_space_regex, "");
               } else if (options.trim_blocks && (it - 1) != begin && !dynamic_cast<ExpressionTemplateToken*>((*(it - 2)).get())) {
                 if (text.length() > 0 && text[0] == '\n') {

diff --git a/tests/test-syntax.cpp b/tests/test-syntax.cpp
@@ -522,6 +522,7 @@ TEST(SyntaxTest, SimpleCases) {
         EXPECT_THAT([]() { render("{% if 1 %}{% else %}", {}, {}); }, ThrowsWithSubstr("Unterminated if"));
         EXPECT_THAT([]() { render("{% if 1 %}{% else %}{% elif 1 %}{% endif %}", {}, {}); }, ThrowsWithSubstr("Unterminated if"));
         EXPECT_THAT([]() { render("{% filter trim %}", {}, {}); }, ThrowsWithSubstr("Unterminated filter"));
+        EXPECT_THAT([]() { render("{# ", {}, {}); }, ThrowsWithSubstr("Missing end of comment tag"));
     }
 
     EXPECT_EQ(