Merge pull request #3902 from facebook/fuzz_debuglevel

Fix fuzz issue 5131069967892480

lib/compress/zstd_opt.c

@@ -1216,6 +1216,7 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
                     if ( (optLevel >= 1) /* additional check only for higher modes */
                       && (prevMatch.litlen == 0) /* replace a match */
                       && (LL_INCPRICE(1) < 0) /* ll1 is cheaper than ll0 */
+                      && LIKELY(ip + cur < iend)
                     ) {
                         /* check next position, in case it would be cheaper */
                         int with1literal = prevMatch.price + LIT_PRICE(ip+cur) + LL_INCPRICE(1);

tests/fuzz/Makefile

@@ -257,7 +257,7 @@ corpora: $(patsubst %,corpora/%,$(FUZZ_TARGETS))
 seedcorpora: $(patsubst %,corpora/%_seed_corpus.zip,$(FUZZ_TARGETS))
 
 regressiontest: corpora
-	CC="$(CC)" CXX="$(CXX)" CFLAGS="$(CFLAGS)" CXXFLAGS="$(CXXFLAGS)" LDFLAGS="$(LDFLAGS)" $(PYTHON) ./fuzz.py build all
+	CC="$(CC)" CXX="$(CXX)" CFLAGS="$(CFLAGS)" CXXFLAGS="$(CXXFLAGS)" LDFLAGS="$(LDFLAGS)" $(PYTHON) ./fuzz.py build all --debug=$(DEBUGLEVEL)
 	$(PYTHON) ./fuzz.py regression all
 
 clean:

tests/fuzz/fuzz.py

@@ -492,6 +492,7 @@ def build(args):
     subprocess.check_call(clean_cmd)
     build_cmd = [
         'make',
+        '-j',
         cc_str,
         cxx_str,
         cppflags_str,