Fix issues reported by oss-fuzz (#729)

* Fix oss-fuzz issue #26529

* Add test for oss-fuzz issue  #26598

* Fix oss-fuzz issue  #26632

* Revert change and add new test cases

httplib.h

@@ -3171,9 +3171,10 @@ get_range_offset_and_length(const Request &req, size_t content_length,
     r.second = slen - 1;
   }
 
-  if (r.second == -1) { r.second = slen - 1; }
-
-  return std::make_pair(r.first, r.second - r.first + 1);
+  if (r.second == -1) {
+    r.second = slen - 1;
+  }
+  return std::make_pair(r.first, static_cast<size_t>(r.second - r.first) + 1);
 }
 
 inline std::string make_content_range_header_field(size_t offset, size_t length,

test/test.cc

@@ -1930,6 +1930,15 @@ TEST_F(ServerTest, GetStreamedWithRangeError) {
   EXPECT_EQ(416, res->status);
 }
 
+//Tests long long overflow.
+TEST_F(ServerTest, GetRangeWithMaxLongLength) {
+  auto res = cli_.Get("/with-range",{{"Range", "bytes=0-9223372036854775807"}});
+  EXPECT_EQ(206, res->status);
+  EXPECT_EQ("7", res->get_header_value("Content-Length"));
+  EXPECT_EQ(true, res->has_header("Content-Range"));
+  EXPECT_EQ(std::string("abcdefg"), res->body);
+}
+
 TEST_F(ServerTest, GetStreamedWithRangeMultipart) {
   auto res =
       cli_.Get("/streamed-with-range", {{make_range_header({{1, 2}, {4, 5}})}});
@@ -2012,6 +2021,12 @@ TEST_F(ServerTest, GetWithRange4) {
   EXPECT_EQ(std::string("fg"), res->body);
 }
 
+//TEST_F(ServerTest, GetWithRangeOffsetGreaterThanContent) {
+//  auto res = cli_.Get("/with-range", {{make_range_header({{10000, 20000}})}});
+//  ASSERT_TRUE(res);
+//  EXPECT_EQ(416, res->status);
+//}
+
 TEST_F(ServerTest, GetWithRangeMultipart) {
   auto res = cli_.Get("/with-range", {{make_range_header({{1, 2}, {4, 5}})}});
   ASSERT_TRUE(res);
@@ -2021,6 +2036,12 @@ TEST_F(ServerTest, GetWithRangeMultipart) {
   EXPECT_EQ(269, res->body.size());
 }
 
+//TEST_F(ServerTest, GetWithRangeMultipartOffsetGreaterThanContent) {
+//  auto res = cli_.Get("/with-range", {{make_range_header({{-1, 2}, {10000, 30000}})}});
+//  ASSERT_TRUE(res);
+//  EXPECT_EQ(416, res->status);
+//}
+
 TEST_F(ServerTest, GetStreamedChunked) {
   auto res = cli_.Get("/streamed-chunked");
   ASSERT_TRUE(res);