Slack Bug 1 - long mrkdwn blocks with ```preformatted``` text

The Issue

#!/bin/sh

# Input to curl is second line and is very long.  Changing the length of the string can change the
# demonstration of the bug.
#
# The output in slack is supposed to be a number of "---...--" lines followed by four blocks
# that say "Here is more info:" followed by ```tables``` of multiple lines.  Sometimes the
# tables are rendered as ```preformatted text``` and sometimes the '```' is rendered as if
# it was not slack code.  It all depends on the length of the message, sometimes shorter works,
# sometimes longer works.  In the following example, the first two blocks work, but the beginning
# of the third block renders as '```' causing it to get messy after that.  I've also seen examples
# where the fourth block is not rendered as preformatted text.

# You need to define your $APPURLGOESHERE to match something that will take and post mrkdown
/usr/bin/curl -k -X POST -H 'Content-type: application/json' -s -S --data @- https://hooks.slack.com/services/$APPURLGOESHERE <<HEREDOC
{"username":"NVRegress Status","channel":"@dmadison","type": "mrkdwn", "text": "----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n----------------------------------------------------------------------------------------\n\nHere is more info:!\n\`\`\`\n       TIME          CL    PASS    FAIL    RUN    PEND    NOTRUN       OPENBUGIDS!\n06/09 05:44    foobarfo     187       0     13       0         0!\n06/09 05:37    foobarfo     194       2      4       0         0 testingtestingtestingtestingtest,testingtestingtestingtestingtest,!\n06/08 05:45    foobarfo     174       0     26       0         0!\n06/08 05:45    foobarfo     180       0     20       0         0                                                                   !\n06/08 05:42    foobarfo     191       0      9       0         0                                                                   !\n\`\`\`\nHere is more info...:\n\`\`\`\n       TIME          CL    PASS    FAIL    RUN    PEND    NOTRUN       OPENBUGIDS!\n06/10 05:38    foobarfo       0     100      0       0         0                                                                   !\n06/10 05:32    foobarfo       0     100      0       0         0                                                                   !\n06/09 05:38    foobarfo       0     100      0       0         0                                                                   !\n06/09 05:38    foobarfo       0     100      0       0         0                                                                   !\n06/08 05:46    foobarfo       0     100      0       0         0                                                                   !\n06/08 05:43    foobarfo       0     100      0       0         0                                                                   !\n\`\`\`\nHere is more info...:\n\`\`\`\n       TIME          CL    PASS    FAIL    RUN    PEND    NOTRUN       OPENBUGIDS!\n06/10 05:39    foobarfo      43       7      0       0         0 testingtestingtestingtestingtest,testingtestingtestingtestingtest,!\n06/10 05:33    foobarfo      43       7      0       0         0 testingtestingtestingtestingtest,testingtestingtestingtestingtest,!\n06/09 05:32    foobarfo      44       6      0       0         0 testingtestingtestingtestingtest,testingtestingtestingtestingtest,!\n06/09 05:32    foobarfo      44       6      0       0         0 testingtestingtestingtestingtest,testingtestingtestingtestingtest,!\n06/08 05:41    foobarfo      46       4      0       0         0 testingtestingtestingtestingtest,testingtestingtestingtestingtest,!\n06/08 05:38    foobarfo      46       4      0       0         0 testingtestingtestingtestingtest,testingtestingtestingtestingtest,!\n\`\`\`\nHere is more info...:\n\`\`\`\n       TIME          CL    PASS    FAIL    RUN    PEND    NOTRUN       OPENBUGIDS!\n06/10 05:31    foobarfo      17      18     15       0         0  http://getdave.com/foo,<http://getdave.com/foo|foobars>!\n06/10 05:29    foobarfo      12      15     23       0         0  http://getdave.com/foo,<http://getdave.com/foo|foobars>!\n06/09 05:34    foobarfo      24      19      7       0         0  http://getdave.com/foo,<http://getdave.com/foo|foobars>!\n06/09 05:31    foobarfo      25      19      6       0         0  http://getdave.com/foo,<http://getdave.com/foo|foobars>!\n06/08 05:35    foobarfo      22      24      4       0         0  http://getdave.com/foo,<http://getdave.com/foo|foobars>!\n06/08 05:32    foobarfo      23      23      4       0         0  http://getdave.com/foo,<http://getdave.com/foo|foobars>!\n\`\`\`\ndone here\n" }
HEREDOC

The Cause

The problem was that the messages were being broken into 4000 character chunks, but that split could happen across formatting such as ``` (though I imagine it could break many, many things, such as being in the midst of an icon, emoji, etc..

Screenshot of the example output:

(click for full size)