Bash – What are the bash shell length limitations for here-docs

What are the length limitations for using here-docs as part of bash command lines? I am finding that short here-docs work fine, but when they get longer there is some point or structure after which they break. When it fails, there are two symptoms. One is that the here-doc is abandoned early. The other is that one or more of the here-doc lines is truncated in the output, and it is not necessarily the last line.

Below you will see a contrived example command with which I can reproduce the problem. The here-doc is a boring 58 lines each containing 79 'x' characters and a newline. If I copy and paste all 60 lines, NOT including the newline from the EOF, to an interactive bash shell, then I must manually hit Enter and the entire command will run successfully every time. However, if I copy and paste all 60 lines, including the EOF newline, then this is when failures occur. If I do the latter in the Terminal application on the desktop, it always fails. If I do it in a remote SSH client, it sometimes works and sometimes fails. Significantly reduce the number of here-doc lines and the problem disappears. The abandoning of the here-doc part way through means that all remaining here-doc lines and the EOF line are seen by bash as new individual command lines, which just results in a flurry of "command not found" errors (or potentially much worse if the here-doc includes legitimate command lines).

cat > ~/test.txt << 'EOF'
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
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EOF

I understand that bash has command line length limits, but this example is well below those limits. In fact, no one line in the above multi-line command is longer than 80 characters and each line gets its own prompt from the shell, so I'm not even sure what limits would apply. It seems odd to me that a here-doc should be limited in length.

I am using Linux Mint 17 (Ubuntu 14.04).

$ bash --version
GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)
...
$ uname -a
Linux QWERTY 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 19:11:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

This problem does not occur when such commands are used from within a bash script.