The files (test) scripts source (with builtin command `.`) provides
information which the scripts depend, and without the `source` to
succeed allowing script to continue may lead to dangerous situations
(e.g. rm -rf "${undefined_variable}"/*).
At the end of all source (.) lines construct ' || exit 1' was added;
In our case the script script will exit if it cannot find (or read) the
file to be sourced. Additionally script would also exits if the last
command of the sourced file exited nonzero.
The difference with FILE_ERROR is that this is for things that are
wrong with the path before looking at the disk.
Add some 3 tests; two broken as a reminder to actually use this new
code.
Quoting Debian bug 787341
It failed to build on arm64: the last ten tests in T070-insert
failed.
What's happening here is that GDB is segfaulting in response to
the
"file" command. GDB on arm64 can be a bit buggy.
However, the "file" command is redundant here as GDB has already
got
the file from the --args on the command line.
Add --keep option to keep any remaining stuff in index or file. We
could distinguish between failures to index and failures to apply tags
or maildir sync, but for simplicity just have one.
All test scripts to be executed are now named as T\d\d\d-name.sh,
numers in increments of 10.
This eases adding new tests and developers to see which are test scripts
that are executed by test suite and in which order.
