fix(radio): Fix handling of blank lines in YAML files (EdgeTX#3762)

* Fix handling of blank lines in YAML files.

* Added some basic EOL / blank line unit tests

---------

Co-authored-by: raphaelcoeffic <[email protected]>

radio/src/storage/yaml/yaml_parser.cpp

@@ -302,15 +302,13 @@ YamlParser::parse(const char* buffer, unsigned int size)
             break;
 
         case ps_CRLF:
-            if (*c == '\n') {
-                // Skip blank lines
-                while (c < end && (*c == '\r' || *c == '\n'))
-                  c += 1;
-                // reset state at EOL
+            // Skip blank lines
+            while (c < end && (*c == '\r' || *c == '\n'))
+                c += 1;
+            // reset state at EOL (unless we have run out of buffer, in case EOL continues in next buffer)
+            if (c < end)
                 reset();
-                continue;
-            }
-            break;
+            continue;
         }
 
         c++;

radio/src/tests/yaml.cpp

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "gtests.h"
+
+#include <storage/yaml/yaml_node.h>
+#include <storage/yaml/yaml_parser.h>
+#include <storage/yaml/yaml_tree_walker.h>
+
+struct TestStruct {
+  uint8_t foo;
+  uint8_t bar;
+
+  TestStruct() : foo(0), bar(0) {}
+};
+
+static const struct YamlNode struct_TestStruct[] = {
+  YAML_UNSIGNED( "foo", 8 ),
+  YAML_UNSIGNED( "bar", 8 ),
+  YAML_END
+};
+
+static const struct YamlNode struct_test[] = {
+  YAML_STRUCT("testStruct", sizeof(TestStruct) * 8, struct_TestStruct, NULL),
+  YAML_END
+};
+
+static const struct YamlNode _root_node = YAML_ROOT( struct_test );
+
+TEST(Yaml, SkipBlankLines)
+{
+  TestStruct t;
+
+  YamlTreeWalker tree;
+  tree.reset(&_root_node, (uint8_t*)&t);
+
+  const char chunk_1[] = "testStruct:\n  foo: 12\n";
+  const char chunk_2[] = "\n  bar: 34\n\n  fo";
+  const char chunk_3[] = "o: 45";
+
+  YamlParser yp;
+  yp.init(YamlTreeWalker::get_parser_calls(), &tree);
+  EXPECT_EQ(YamlParser::CONTINUE_PARSING, yp.parse(chunk_1, sizeof(chunk_1) - 1));
+  EXPECT_EQ(12, t.foo);
+
+  EXPECT_EQ(YamlParser::CONTINUE_PARSING, yp.parse(chunk_2, sizeof(chunk_2) - 1));
+  EXPECT_EQ(34, t.bar);
+
+  yp.set_eof();
+  EXPECT_EQ(YamlParser::CONTINUE_PARSING, yp.parse(chunk_3, sizeof(chunk_3) - 1));
+  EXPECT_EQ(45, t.foo);
+}