[Net] Fix HTTPRequest gzip with high compression ratio.

Decompress each body chunk over multiple iterations, this causes more
reallocations, but it ensures decompression will not fail no matter the
compression ratio.

scene/main/http_request.cpp

@@ -276,10 +276,10 @@ bool HTTPRequest::_handle_response(bool *ret_value) {
 	}
 	if (content_encoding == "gzip") {
 		decompressor.instantiate();
-		decompressor->start_decompression(false, get_download_chunk_size() * 2);
+		decompressor->start_decompression(false, get_download_chunk_size());
 	} else if (content_encoding == "deflate") {
 		decompressor.instantiate();
-		decompressor->start_decompression(true, get_download_chunk_size() * 2);
+		decompressor->start_decompression(true, get_download_chunk_size());
 	}
 
 	return false;
@@ -390,19 +390,38 @@ bool HTTPRequest::_update_connection() {
 				return false;
 			}
 
-			PackedByteArray chunk = client->read_response_body_chunk();
-			downloaded.add(chunk.size());
-
-			// Decompress chunk if needed.
-			if (decompressor.is_valid()) {
-				Error err = decompressor->put_data(chunk.ptr(), chunk.size());
-				if (err == OK) {
-					chunk.resize(decompressor->get_available_bytes());
-					err = decompressor->get_data(chunk.ptrw(), chunk.size());
-				}
-				if (err != OK) {
-					_defer_done(RESULT_BODY_DECOMPRESS_FAILED, response_code, response_headers, PackedByteArray());
-					return true;
+			PackedByteArray chunk;
+			if (decompressor.is_null()) {
+				// Chunk can be read directly.
+				chunk = client->read_response_body_chunk();
+				downloaded.add(chunk.size());
+			} else {
+				// Chunk is the result of decompression.
+				PackedByteArray compressed = client->read_response_body_chunk();
+				downloaded.add(compressed.size());
+
+				int pos = 0;
+				int left = compressed.size();
+				while (left) {
+					int w = 0;
+					Error err = decompressor->put_partial_data(compressed.ptr() + pos, left, w);
+					if (err == OK) {
+						PackedByteArray dc;
+						dc.resize(decompressor->get_available_bytes());
+						err = decompressor->get_data(dc.ptrw(), dc.size());
+						chunk.append_array(dc);
+					}
+					if (err != OK) {
+						_defer_done(RESULT_BODY_DECOMPRESS_FAILED, response_code, response_headers, PackedByteArray());
+						return true;
+					}
+					// We need this check here because a "zip bomb" could result in a chunk of few kilos decompressing into gigabytes of data.
+					if (body_size_limit >= 0 && final_body_size.get() + chunk.size() > body_size_limit) {
+						_defer_done(RESULT_BODY_SIZE_LIMIT_EXCEEDED, response_code, response_headers, PackedByteArray());
+						return true;
+					}
+					pos += w;
+					left -= w;
 				}
 			}
 			final_body_size.add(chunk.size());