cabana: fix parsing multiple line comment (#30178)

fix parse error
old-commit-hash: 29f10fd2aa

tools/cabana/dbc/dbcfile.cc

@@ -107,7 +107,8 @@ void DBCFile::parse(const QString &content) {
   int multiplexor_cnt = 0;
   while (!stream.atEnd()) {
     ++line_num;
-    line = stream.readLine().trimmed();
+    QString raw_line = stream.readLine();
+    line = raw_line.trimmed();
     if (line.startsWith("BO_ ")) {
       multiplexor_cnt = 0;
       auto match = bo_regexp.match(line);
@@ -170,7 +171,7 @@ void DBCFile::parse(const QString &content) {
       }
     } else if (line.startsWith("CM_ BO_")) {
       if (!line.endsWith("\";")) {
-        int pos = stream.pos() - line.length() - 1;
+        int pos = stream.pos() - raw_line.length() - 1;
         line = content.mid(pos, content.indexOf("\";", pos));
       }
       auto match = msg_comment_regexp.match(line);
@@ -180,7 +181,7 @@ void DBCFile::parse(const QString &content) {
       }
     } else if (line.startsWith("CM_ SG_ ")) {
       if (!line.endsWith("\";")) {
-        int pos = stream.pos() - line.length() - 1;
+        int pos = stream.pos() - raw_line.length() - 1;
         line = content.mid(pos, content.indexOf("\";", pos));
       }
       auto match = sg_comment_regexp.match(line);

tools/cabana/tests/test_cabana.cc

@@ -69,7 +69,7 @@ TEST_CASE("Parse can messages") {
   }
 }
 
-TEST_CASE("Parse dbc") {
+TEST_CASE("parse_dbc") {
   QString content = R"(
 BO_ 160 message_1: 8 EON
   SG_ signal_1 : 0|12@1+ (1,0) [0|4095] "unit"  XXX
@@ -83,7 +83,7 @@ VAL_ 160 signal_1 0 "disabled" 1.2 "initializing" 2 "fault";
 
 CM_ BO_ 160 "message comment" ;
 CM_ SG_ 160 signal_1 "signal comment";
-CM_ SG_ 160 signal_2 "multiple line comment
+CM_ SG_ 160 signal_2 "multiple line comment 
 1
 2
 ";)";
@@ -113,7 +113,7 @@ CM_ SG_ 160 signal_2 "multiple line comment
   REQUIRE(sig_1->val_desc[2] == std::pair<double, QString>{2, "fault"});
 
   auto &sig_2 = msg->sigs[1];
-  REQUIRE(sig_2->comment == "multiple line comment\n1\n2");
+  REQUIRE(sig_2->comment == "multiple line comment \n1\n2");
 
   // multiplexed signals
   msg = file.msg(162);