There is a bug in `width_bucket()` causing an overflow and subsequent
NaN value as a result of dividing with `+inf`. The NaN value is
interpreted as an integer and hence generates an index out of range for
the buckets.
This commit fixes this by generating an error rather than
segfaulting for bucket indexes that are out of range.
Since the number of buckets of the histogram function is an argument
to the function call it is possible to initialize the histogram
state with a lower number than actually needed in further calls
leading to a segfault. This patch changes the memory access to use
the number the state was initialized with instead of the number
passed to the call. This also changes the function to error when
the passed number differs from the initialized state.
The extension now works with PostgreSQL 10, while
retaining compatibility with version 9.6.
PostgreSQL 10 has numerous internal changes to functions and
APIs, which necessitates various glue code and compatibility
wrappers to seamlessly retain backwards compatiblity with older
versions.
Test output might also differ between versions. In particular,
the psql client generates version-specific output with `\d` and
EXPLAINs might differ due to new query optimizations. The test
suite has been modified as follows to handle these issues. First,
tests now use version-independent functions to query system
catalogs instead of using `\d`. Second, changes have been made to
the test suite to be able to verify some test outputs against
version-dependent reference files.
This commit moves a lot of test setup logic to runner.sh. Also
passes the right commands to the regression infrastructure to create
appropriate users and run tests as a regular user.
