optimise .cw exporting for C client

src/Client/Bitmap.c

@@ -655,9 +655,12 @@ ReturnCode Bitmap_EncodePng(struct Bitmap* bmp, struct Stream* stream) {
 			UInt8* prev = (y & 1) == 0 ? prevLine : curLine;
 			UInt8* cur  = (y & 1) == 0 ? curLine : prevLine;
 			Png_EncodeRow(src, cur, prev, bestLine, lineSize);
-			Stream_Write(&zlStream, bestLine, lineSize + 1); /* +1 for filter byte */
+
+			result = Stream_TryWrite(&zlStream, bestLine, lineSize + 1); /* +1 for filter byte */
+			if (result) return result;
 		}
-		zlStream.Close(&zlStream);
+		result = zlStream.Close(&zlStream);
+		if (result) return result;
 	}
 	stream = underlying;
 	Stream_WriteU32_BE(stream, crc32Stream.Meta.CRC32.CRC32 ^ 0xFFFFFFFFUL);
@@ -676,6 +679,6 @@ ReturnCode Bitmap_EncodePng(struct Bitmap* bmp, struct Stream* stream) {
 	result = stream->Seek(stream, 33, STREAM_SEEKFROM_BEGIN);
 	if (result) return result;
 
-	Stream_WriteU32_BE(stream, stream_len - 57);
-	return 0;
+	Stream_SetU32_BE(&tmp[0], stream_len - 57);
+	return Stream_TryWrite(stream, tmp, sizeof(UInt32));
 }

src/Client/Chat.c

@@ -131,7 +131,10 @@ static void Chat_AppendLog(STRING_PURE String* text) {
 	String_Format3(&str, "[%p2:%p2:%p2] ", &hour, &minute, &second);
 	String_AppendColorless(&str, text);
 
-	Stream_WriteLine(&Chat_LogStream, &str);
+	ReturnCode result = Stream_WriteLine(&Chat_LogStream, &str);
+	if (!result) return;
+	ErrorHandler_LogError_Path(result, "appending to", &Chat_LogStream.Name);
+	Chat_DisableLogging(); return;
 }
 
 void Chat_AddRaw(const UChar* raw) {