Resubmission of #2001. This switches the `sed` invocations to use `-E`,
extended regex syntax, which is better standardized across platforms.
I guess.
Same test plan:
```
make -C lib clean libzstd.pc
cat lib/libzstd.pc
echo # should fail
make -C lib clean libzstd.pc LIBDIR=/foo
make -C lib clean libzstd.pc INCLUDEDIR=/foo
make -C lib clean libzstd.pc LIBDIR=/usr/localfoo
make -C lib clean libzstd.pc INCLUDEDIR=/usr/localfoo
make -C lib clean libzstd.pc LIBDIR=/usr/local/lib prefix=/foo
make -C lib clean libzstd.pc INCLUDEDIR=/usr/local/include prefix=/foo
echo # should succeed
make -C lib clean libzstd.pc LIBDIR=/usr/local/foo
make -C lib clean libzstd.pc INCLUDEDIR=/usr/local/foo
make -C lib clean libzstd.pc LIBDIR=/usr/local/
make -C lib clean libzstd.pc INCLUDEDIR=/usr/local/
make -C lib clean libzstd.pc LIBDIR=/usr/local
make -C lib clean libzstd.pc INCLUDEDIR=/usr/local
make -C lib clean libzstd.pc LIBDIR=/tmp/foo prefix=/tmp
make -C lib clean libzstd.pc INCLUDEDIR=/tmp/foo prefix=/tmp
make -C lib clean libzstd.pc LIBDIR=/tmp/foo prefix=/tmp/foo
make -C lib clean libzstd.pc INCLUDEDIR=/tmp/foo prefix=/tmp/foo
echo # should also succeed
make -C lib clean libzstd.pc prefix=/foo LIBDIR=/foo/bar INCLUDEDIR=/foo/
cat lib/libzstd.pc
mkdir out
cd out
cmake ../build/cmake
make
cat lib/libzstd.pc
```
When the output buffer is `NULL` with size 0, but the frame content size
is non-zero, we will write to the NULL pointer because our bounds check
underflowed.
This was exposed by a recent PR that allowed an empty frame into the
single-pass shortcut in streaming mode.
* Fix the bug.
* Fix another NULL dereference in zstd-v1.
* Overflow checks in 32-bit mode.
* Add a dedicated test.
* Expose the bug in the dedicated simple_decompress fuzzer.
* Switch all mallocs in fuzzers to return NULL for size=0.
* Fix a new timeout in a fuzzer.
Neither clang nor gcc show a decompression speed regression on x86-64.
On x86-32 clang is slightly positive and gcc loses 2.5% of speed.
Credit to OSS-Fuzz.
The cygwin test on Appveyor is way too long (>30 mn).
The main issue is the very long zstreamtest, because no time out has been programmed.
Ensures that both fuzzer and zstreamtest receive a 30sec slot.
Should reduce cygwin tests duration by -30mn.
This diff reorganizes the `lib/Makefile` to extract various settings that a
user would normally invoke together (supposing that they were aware of them)
if they were trying to build the smallest `libzstd` possible. It collects
these settings under a master setting `ZSTD_LIB_MIN_SIZE`.
Also document this new option.
It's complaining about the `memcpy`s, saying:
"warning C4090: 'function': different 'const' qualifiers"
Let's try explicitly casting to the argument types...
