In pixman-fast-path.c: (1 << 31) - 1 causes a signed overflow, so
change to (1U << n) - 1.
In pixman-image.c: The check for whether m10 == -m01 will overflow
when -m01 == INT_MIN. Instead just check whether the variables are 1
and -1.
In pixman-utils.c: When the depth of the topmost channel is 0, we can
end up shifting by 32.
In blitters-test.c: Replicating the mask would end up shifting more
than 32.
In region-contains-test.c: Computing the average of two large integers
could overflow. Instead add half the difference between them to the
first integer.
In stress-test.c: Masking the value in fake_reader() would sometimes
shift by 32. Instead just use the most significant bits instead of
the least significant.
All these issues were found by the IOC tool:
http://embed.cs.utah.edu/ioc/
All the tests are linked to libutil, hence it makes sence to always
include utils.h and reuse what it provides (config.h inclusion, access
to private pixman APIs, ARRAY_LENGTH, ...).
This patch makes so that composite and stress-test will start from a
random seed if the PIXMAN_RANDOMIZE_TESTS environment variable is
set. Running the test suite in this mode is useful to get more test
coverage.
Also, in stress-test.c make it so that setting the initial seed causes
threads to be turned off. This makes it much easier to see when
something fails.
MSVC does not notice non-returning functions (abort() / assert(0))
and warns about paths which end with them in non-void functions:
c:\cygwin\home\ranma42\code\fdo\pixman\test\fetch-test.c(114) :
warning C4715: 'reader' : not all control paths return a value
c:\cygwin\home\ranma42\code\fdo\pixman\test\stress-test.c(133) :
warning C4715: 'real_reader' : not all control paths return a value
c:\cygwin\home\ranma42\code\fdo\pixman\test\composite.c(431) :
warning C4715: 'calc_op' : not all control paths return a value
These warnings can be silenced by adding a return after the
termination call.
This test program tries to use as many rarely-used features as
possible, including alpha maps, accessor functions, oddly-sized
images, strange transformations, conical gradients, etc.
The hope is to provoke crashes or irregular behavior in pixman.
