[BUG] Trace output of ESP32-DevKitC jobs demo is clobbered

[cookpate]

Describe the bug
A help message is printed out when the jobs_for_aws demo first runs. On the ESP32 DevKit at least, the message ends up clobbered and doesn't print out in full. I initially thought I was going to a dead link in the docs.

System information

• Hardware board: ESP32-DevKitC
• IDE used: ESP-IDF
• Operating System: Windows
• Code version: 202107.00-81-g49e7fe5d6
• Project/Demo: Jobs_Demo

Expected behavior
The help message should be displayed in full without any clobbering as shown:

amazon-freertos/demos/jobs_for_aws/jobs_demo.c

Lines 828 to 854 in 49e7fe5

	LogInfo( ( "\r\n"
	"/*-----------------------------------------------------------*/\r\n"
	"\r\n"
	"The Jobs demo is now ready to accept Jobs.\r\n"
	"Jobs may be created using the AWS IoT console or AWS CLI.\r\n"
	"See the following link for more information.\r\n" ) );
	LogInfo( ( "\r"
	"https://docs.aws.amazon.com/cli/latest/reference/iot/create-job.html\r\n"
	"\r\n"
	"This demo expects Job documents to have an \"action\" JSON key.\r\n"
	"The following actions are currently supported:\r\n" ) );
	LogInfo( ( "\r"
	" - print \r\n"
	" Logs a message to the local console. The Job document must also contain a \"message\".\r\n"
	" For example: { \"action\": \"print\", \"message\": \"Hello world!\"} will cause\r\n"
	" \"Hello world!\" to be printed on the console.\r\n" ) );
	LogInfo( ( "\r"
	" - publish \r\n"
	" Publishes a message to an MQTT topic. The Job document must also contain a \"message\" and \"topic\".\r\n" ) );
	LogInfo( ( "\r"
	" For example: { \"action\": \"publish\", \"topic\": \"demo/jobs\", \"message\": \"Hello world!\"} will cause\r\n"
	" \"Hello world!\" to be published to the topic \"demo/jobs\".\r\n" ) );
	LogInfo( ( "\r"
	" - exit \r\n"
	" Exits the demo program. This program will run until { \"action\": \"exit\" } is received.\r\n"
	"\r\n"
	"/*-----------------------------------------------------------*/\r\n" ) );

Screenshots or console output

14 495 [iot_thread] [jobs_demo.c:833] [INFO] [JobsDemo]
/*-----------------------------------------------------------*/

The Jobs demo is now ready to accept Jobs.
https://docs.aws.amazon.com/cli/latest/reference/iot/create-job.htmlJobsDemo]

 - print          ] [jobs_demo.c:843] [INFO] [JobsDemo]  key.
   Logs a message to the local console. The Job document must also contain a "message".
 - publish        "action17 495 [iot_thread] [jobs_demo.c:846] [INFO] [JobsDemo]
   Publishes a message to an MQTT topic. The Job document must also contain a "message" and "topic".


   For example: { "action": "publish", "topic": "demo/jobs", "message": "Hello world!"} will cause
 - exit           to be published 19 495 [iot_thread] [jobs_demo.c:854] [INFO] [JobsDemo]
   Exits the demo program. This program will run until { "action": "exit" } is received.

/*--------------------20 495 [iot_thread] [mqtt_demo_helpers.c:565] [INFO] [MQTT] Attempt to subscribe to the MQTT topic $aws/things/cookpateESP32-TestBoard/jobs/notify-next.

Steps to reproduce bug
Example:
1. Configure to run the Jobs Demo (#define CONFIG_JOBS_DEMO_ENABLED in aws_demo_config.h)
2. In the root directory with a configured ESP32 thing plugged in, flash and monitor the demo

[cookpate]

This actually looks more like a race condition in LogInfo for this demo. IT should have printed out an example job, but this is an example console output in the ESP-IDF 4.2 PowerShell window:

14 495 [iot_thread] [jobs_demo.c:833] [INFO] [JobsDemo]
/*-----------------------------------------------------------*/

The Jobs demo is now ready to accept Jobs.
https://docs.aws.amazon.com/cli/latest/reference/iot/create-job.htmlJobsDemo]

 - print          ] [jobs_demo.c:843] [INFO] [JobsDemo]  key.
   Logs a message to the local console. The Job document must also contain a "message".
 - publish        "action17 495 [iot_thread] [jobs_demo.c:846] [INFO] [JobsDemo]
   Publishes a message to an MQTT topic. The Job document must also contain a "message" and "topic".


   For example: { "action": "publish", "topic": "demo/jobs", "message": "Hello world!"} will cause
 - exit           to be published 19 495 [iot_thread] [jobs_demo.c:854] [INFO] [JobsDemo]
   Exits the demo program. This program will run until { "action": "exit" } is received.

/*--------------------20 495 [iot_thread] [mqtt_demo_helpers.c:565] [INFO] [MQTT] Attempt to subscribe to the MQTT topic $aws/things/cookpateESP32-TestBoard/jobs/notify-next.

This is printed out from here:

amazon-freertos/demos/jobs_for_aws/jobs_demo.c

Lines 828 to 854 in 49e7fe5

	LogInfo( ( "\r\n"
	"/*-----------------------------------------------------------*/\r\n"
	"\r\n"
	"The Jobs demo is now ready to accept Jobs.\r\n"
	"Jobs may be created using the AWS IoT console or AWS CLI.\r\n"
	"See the following link for more information.\r\n" ) );
	LogInfo( ( "\r"
	"https://docs.aws.amazon.com/cli/latest/reference/iot/create-job.html\r\n"
	"\r\n"
	"This demo expects Job documents to have an \"action\" JSON key.\r\n"
	"The following actions are currently supported:\r\n" ) );
	LogInfo( ( "\r"
	" - print \r\n"
	" Logs a message to the local console. The Job document must also contain a \"message\".\r\n"
	" For example: { \"action\": \"print\", \"message\": \"Hello world!\"} will cause\r\n"
	" \"Hello world!\" to be printed on the console.\r\n" ) );
	LogInfo( ( "\r"
	" - publish \r\n"
	" Publishes a message to an MQTT topic. The Job document must also contain a \"message\" and \"topic\".\r\n" ) );
	LogInfo( ( "\r"
	" For example: { \"action\": \"publish\", \"topic\": \"demo/jobs\", \"message\": \"Hello world!\"} will cause\r\n"
	" \"Hello world!\" to be published to the topic \"demo/jobs\".\r\n" ) );
	LogInfo( ( "\r"
	" - exit \r\n"
	" Exits the demo program. This program will run until { \"action\": \"exit\" } is received.\r\n"
	"\r\n"
	"/*-----------------------------------------------------------*/\r\n" ) );

[cookpate]

Ah, it looks like the carriage return at the beginning of log messages isn't overwriting the current line. It's a hacky way of suppressing the log message header.