LibIMAP: Propagate errors from Parser::parse_number()

More error propagation is still needed, we really want the parser to
just crash early when it encounters unexpected input, instead of trying
to carry on like nothing happened.
I think ErrorOr<unsigned> is *much* better than returning (unsigned)-1
to indicate an error ;)

Userland/Libraries/LibIMAP/Parser.cpp

@@ -71,7 +71,7 @@ bool Parser::try_consume(StringView x)
 void Parser::parse_response_done()
 {
  consume("A"sv);
- auto tag = parse_number();
+ auto tag = MUST(parse_number());
  consume(" "sv);
 
  ResponseStatus status = parse_status();
@@ -119,12 +119,12 @@ Optional<unsigned> Parser::try_parse_number()
  return number.to_uint();
 }
 
-unsigned Parser::parse_number()
+ErrorOr<unsigned> Parser::parse_number()
 {
  auto number = try_parse_number();
  if (!number.has_value()) {
  m_parsing_failed = true;
- return -1;
+ return Error::from_string_view("Failed to parse expected number"sv);
  }
 
  return number.value();
@@ -177,23 +177,23 @@ void Parser::parse_untagged()
  // No-op.
  } else if (actual_type == "UIDNEXT"sv) {
  consume(" "sv);
- auto n = parse_number();
+ auto n = MUST(parse_number());
  m_response.data().set_uid_next(n);
  } else if (actual_type == "UIDVALIDITY"sv) {
  consume(" "sv);
- auto n = parse_number();
+ auto n = MUST(parse_number());
  m_response.data().set_uid_validity(n);
  } else if (actual_type == "UNSEEN"sv) {
  consume(" "sv);
- auto n = parse_number();
+ auto n = MUST(parse_number());
  m_response.data().set_unseen(n);
  } else if (actual_type == "PERMANENTFLAGS"sv) {
  consume(" "sv);
  auto flags = parse_list(+[](StringView x) { return DeprecatedString(x); });
  m_response.data().set_permanent_flags(move(flags));
  } else if (actual_type == "HIGHESTMODSEQ"sv) {
  consume(" "sv);
- parse_number();
+ MUST(parse_number());
  // No-op for now.
  } else {
  dbgln("Unknown: {}", actual_type);
@@ -207,7 +207,7 @@ void Parser::parse_untagged()
  Vector<unsigned> ids;
  while (!try_consume("\r\n"sv)) {
  consume(" "sv);
- auto id = parse_number();
+ auto id = MUST(parse_number());
  ids.append(id);
  }
  m_response.data().set_search_results(move(ids));
@@ -224,7 +224,7 @@ void Parser::parse_untagged()
  while (!try_consume(")"sv)) {
  auto status_att = parse_atom();
  consume(" "sv);
- auto value = parse_number();
+ auto value = MUST(parse_number());
 
  auto type = StatusItemType::Recent;
  if (status_att == "MESSAGES"sv) {
@@ -318,7 +318,7 @@ FetchResponseData Parser::parse_fetch_response()
  }
  case FetchCommand::DataItemType::UID: {
  consume(" "sv);
- fetch_response.set_uid(parse_number());
+ fetch_response.set_uid(MUST(parse_number()));
  break;
  }
  case FetchCommand::DataItemType::PeekBody:
@@ -439,9 +439,9 @@ BodyStructure Parser::parse_one_part_body()
  consume(" "sv);
  auto encoding = parse_string();
  consume(" "sv);
- auto num_octets = parse_number();
+ auto num_octets = MUST(parse_number());
  consume(" "sv);
- auto num_lines = parse_number();
+ auto num_lines = MUST(parse_number());
 
  auto data = BodyStructureData {
  type,
@@ -501,7 +501,7 @@ BodyStructure Parser::parse_one_part_body()
  consume(" "sv);
  auto encoding = parse_string();
  consume(" "sv);
- auto num_octets = parse_number();
+ auto num_octets = MUST(parse_number());
  consume(" "sv);
  auto envelope = parse_envelope();
 
@@ -528,7 +528,7 @@ BodyStructure Parser::parse_one_part_body()
  consume(" "sv);
  auto encoding = parse_string();
  consume(" "sv);
- auto num_octets = parse_number();
+ auto num_octets = MUST(parse_number());
  consume(" "sv);
 
  BodyStructureData data {
@@ -572,7 +572,7 @@ StringView Parser::parse_literal_string()
 {
  dbgln_if(IMAP_PARSER_DEBUG, "p: {}, parse_literal_string()", m_position);
  consume("{"sv);
- auto num_bytes = parse_number();
+ auto num_bytes = MUST(parse_number());
  consume("}\r\n"sv);
 
  if (m_buffer.size() < m_position + num_bytes) {
@@ -772,7 +772,7 @@ FetchCommand::DataItem Parser::parse_fetch_data_item()
  m_parsing_failed = true;
  }
  if (try_consume("<"sv)) {
- auto start = parse_number();
+ auto start = MUST(parse_number());
  data_item.partial_fetch = true;
  data_item.start = (int)start;
  consume(">"sv);
@@ -876,7 +876,7 @@ BodyExtension Parser::parse_body_extension()
  } else if (!at_end() && (m_buffer[m_position] == '"' || m_buffer[m_position] == '{')) {
  return BodyExtension { { parse_string() } };
  } else {
- return BodyExtension { parse_number() };
+ return BodyExtension { MUST(parse_number()) };
  }
 }
 }

Userland/Libraries/LibIMAP/Parser.h

@@ -32,7 +32,7 @@ class Parser {
 
  bool at_end() { return m_position >= m_buffer.size(); }
 
- unsigned parse_number();
+ ErrorOr<unsigned> parse_number();
  Optional<unsigned> try_parse_number();
 
  void parse_response_done();