Fix the write function to return the actual number of bytes sent.

[BetterComputing]

The write function was always returning the same count of bytes as was passed in because the size variable was not being assigned the actual number of bytes sent. For example, if I am using a WIZNet 5500 (which limits the send size to 2048 bytes) and I call the function as follows:

size_t bytesSent = pClient->write(pBuffer, 8192);

The result returned into the variable bytesSent will be 8192, even though only 2048 bytes were actually sent.

The change to EthernetClient.cpp in this fork fixes the bug.

[github-actions[bot]]

Memory usage change @ fdec9ee314aa34fdb8a2c3446af807c15cedfde8

Board	flash	%	RAM for global variables	%
arduino:avr:leonardo	:green_heart: -14 - 0	-0.05 - 0.0	0 - 0	0.0 - 0.0
arduino:avr:mega	:green_heart: -14 - 0	-0.01 - 0.0	0 - 0	0.0 - 0.0
arduino:avr:nano	:green_heart: -14 - 0	-0.05 - 0.0	0 - 0	0.0 - 0.0
arduino:megaavr:nona4809	:grey_question: -14 - +8	-0.03 - +0.02	0 - 0	0.0 - 0.0
arduino:megaavr:uno2018	:grey_question: -14 - +8	-0.03 - +0.02	0 - 0	0.0 - 0.0
arduino:sam:arduino_due_x_dbg	:green_heart: -8 - 0	-0.0 - 0.0	N/A	N/A
arduino:samd:arduino_zero_edbg	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkr1000	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrfox1200	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrgsm1400	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrnb1500	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrvidor4000	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrwan1300	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrwan1310	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrwifi1010	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrzero	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:nano_33_iot	:green_heart: -4 - 0	-0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/AdvancedChatServer flash	%	examples/AdvancedChatServer RAM for global variables	%	examples/BarometricPressureWebServer flash	%	examples/BarometricPressureWebServer RAM for global variables	%	examples/ChatServer flash	%	examples/ChatServer RAM for global variables	%	examples/DhcpAddressPrinter flash	%	examples/DhcpAddressPrinter RAM for global variables	%	examples/DhcpChatServer flash	%	examples/DhcpChatServer RAM for global variables	%	examples/LinkStatus flash	%	examples/LinkStatus RAM for global variables	%	examples/PagerServer flash	%	examples/PagerServer RAM for global variables	%	examples/TelnetClient flash	%	examples/TelnetClient RAM for global variables	%	examples/UDPSendReceiveString flash	%	examples/UDPSendReceiveString RAM for global variables	%	examples/UdpNtpClient flash	%	examples/UdpNtpClient RAM for global variables	%	examples/WebClient flash	%	examples/WebClient RAM for global variables	%	examples/WebClientRepeating flash	%	examples/WebClientRepeating RAM for global variables	%	examples/WebServer flash	%	examples/WebServer RAM for global variables	%
arduino:avr:leonardo	-14	-0.05	0	0.0	-14	-0.05	0	0.0	-14	-0.05	0	0.0	0	0.0	0	0.0	-14	-0.05	0	0.0	0	0.0	0	0.0	-14	-0.05	0	0.0	-10	-0.03	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-10	-0.03	0	0.0	-10	-0.03	0	0.0	-14	-0.05	0	0.0
arduino:avr:mega	-14	-0.01	0	0.0	-14	-0.01	0	0.0	-14	-0.01	0	0.0	0	0.0	0	0.0	-14	-0.01	0	0.0	0	0.0	0	0.0	-14	-0.01	0	0.0	-10	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-10	-0.0	0	0.0	-10	-0.0	0	0.0	-14	-0.01	0	0.0
arduino:avr:nano	-14	-0.05	0	0.0	-14	-0.05	0	0.0	-14	-0.05	0	0.0	0	0.0	0	0.0	-14	-0.05	0	0.0	0	0.0	0	0.0	-14	-0.05	0	0.0	-10	-0.03	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-10	-0.03	0	0.0	-10	-0.03	0	0.0	-14	-0.05	0	0.0
arduino:megaavr:nona4809	-14	-0.03	0	0.0	-14	-0.03	0	0.0	-14	-0.03	0	0.0	0	0.0	0	0.0	-14	-0.03	0	0.0	0	0.0	0	0.0	-14	-0.03	0	0.0	8	0.02	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	8	0.02	0	0.0	8	0.02	0	0.0	-14	-0.03	0	0.0
arduino:megaavr:uno2018	-14	-0.03	0	0.0	-14	-0.03	0	0.0	-14	-0.03	0	0.0	0	0.0	0	0.0	-14	-0.03	0	0.0	0	0.0	0	0.0	-14	-0.03	0	0.0	8	0.02	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	8	0.02	0	0.0	8	0.02	0	0.0	-14	-0.03	0	0.0
arduino:sam:arduino_due_x_dbg	-8	-0.0	N/A	N/A	-8	-0.0	N/A	N/A	-8	-0.0	N/A	N/A	0	0.0	N/A	N/A	-8	-0.0	N/A	N/A	0	0.0	N/A	N/A	-8	-0.0	N/A	N/A	0	0.0	N/A	N/A	0	0.0	N/A	N/A	0	0.0	N/A	N/A	-8	-0.0	N/A	N/A	-8	-0.0	N/A	N/A	-8	-0.0	N/A	N/A
arduino:samd:arduino_zero_edbg	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkr1000	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrfox1200	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrgsm1400	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrnb1500	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrvidor4000	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrwan1300	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrwan1310	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrwifi1010	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:mkrzero	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0
arduino:samd:nano_33_iot	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0	-4	-0.0	0	0.0

Click for full report CSV

Board,examples/AdvancedChatServer<br>flash,%,examples/AdvancedChatServer<br>RAM for global variables,%,examples/BarometricPressureWebServer<br>flash,%,examples/BarometricPressureWebServer<br>RAM for global variables,%,examples/ChatServer<br>flash,%,examples/ChatServer<br>RAM for global variables,%,examples/DhcpAddressPrinter<br>flash,%,examples/DhcpAddressPrinter<br>RAM for global variables,%,examples/DhcpChatServer<br>flash,%,examples/DhcpChatServer<br>RAM for global variables,%,examples/LinkStatus<br>flash,%,examples/LinkStatus<br>RAM for global variables,%,examples/PagerServer<br>flash,%,examples/PagerServer<br>RAM for global variables,%,examples/TelnetClient<br>flash,%,examples/TelnetClient<br>RAM for global variables,%,examples/UDPSendReceiveString<br>flash,%,examples/UDPSendReceiveString<br>RAM for global variables,%,examples/UdpNtpClient<br>flash,%,examples/UdpNtpClient<br>RAM for global variables,%,examples/WebClient<br>flash,%,examples/WebClient<br>RAM for global variables,%,examples/WebClientRepeating<br>flash,%,examples/WebClientRepeating<br>RAM for global variables,%,examples/WebServer<br>flash,%,examples/WebServer<br>RAM for global variables,%
arduino:avr:leonardo,-14,-0.05,0,0.0,-14,-0.05,0,0.0,-14,-0.05,0,0.0,0,0.0,0,0.0,-14,-0.05,0,0.0,0,0.0,0,0.0,-14,-0.05,0,0.0,-10,-0.03,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-10,-0.03,0,0.0,-10,-0.03,0,0.0,-14,-0.05,0,0.0
arduino:avr:mega,-14,-0.01,0,0.0,-14,-0.01,0,0.0,-14,-0.01,0,0.0,0,0.0,0,0.0,-14,-0.01,0,0.0,0,0.0,0,0.0,-14,-0.01,0,0.0,-10,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-10,-0.0,0,0.0,-10,-0.0,0,0.0,-14,-0.01,0,0.0
arduino:avr:nano,-14,-0.05,0,0.0,-14,-0.05,0,0.0,-14,-0.05,0,0.0,0,0.0,0,0.0,-14,-0.05,0,0.0,0,0.0,0,0.0,-14,-0.05,0,0.0,-10,-0.03,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-10,-0.03,0,0.0,-10,-0.03,0,0.0,-14,-0.05,0,0.0
arduino:megaavr:nona4809,-14,-0.03,0,0.0,-14,-0.03,0,0.0,-14,-0.03,0,0.0,0,0.0,0,0.0,-14,-0.03,0,0.0,0,0.0,0,0.0,-14,-0.03,0,0.0,8,0.02,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,8,0.02,0,0.0,8,0.02,0,0.0,-14,-0.03,0,0.0
arduino:megaavr:uno2018,-14,-0.03,0,0.0,-14,-0.03,0,0.0,-14,-0.03,0,0.0,0,0.0,0,0.0,-14,-0.03,0,0.0,0,0.0,0,0.0,-14,-0.03,0,0.0,8,0.02,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,8,0.02,0,0.0,8,0.02,0,0.0,-14,-0.03,0,0.0
arduino:sam:arduino_due_x_dbg,-8,-0.0,N/A,N/A,-8,-0.0,N/A,N/A,-8,-0.0,N/A,N/A,0,0.0,N/A,N/A,-8,-0.0,N/A,N/A,0,0.0,N/A,N/A,-8,-0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A,-8,-0.0,N/A,N/A,-8,-0.0,N/A,N/A,-8,-0.0,N/A,N/A
arduino:samd:arduino_zero_edbg,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkr1000,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrfox1200,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrgsm1400,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrnb1500,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrvidor4000,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrwan1300,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrwan1310,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrwifi1010,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:mkrzero,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0
arduino:samd:nano_33_iot,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0,-4,-0.0,0,0.0

[per1234]

Thanks @BetterComputing. For the sake of making the information available to the reviewers, I'll note here the two other alternative proposals that have been submitted for fixing this bug:

• https://github.com/arduino-libraries/Ethernet/pull/142
• https://github.com/arduino-libraries/Ethernet/pull/187