From: Yann Collet <cyan@fb.com>
Date: Thu, 11 Jan 2018 04:33:45 +0000 (-0800)
Subject: fixed bug #976, reported by @indygreg
X-Git-Tag: v1.3.4~1^2~89^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ff795580f2e9acb02d1a68b9e2f1d4a17a4e3343;p=thirdparty%2Fzstd.git

fixed bug #976, reported by @indygreg

constants in zstd.h should not depend on MIN() macro which existence is not guaranteed.

Added a test to check the specific constants.
The test is a bit too specific.
But I have found no way to control a more generic "are all macro already defined" condition,
especially as this is a valid construction (the missing macro might be defined later, intentionnally).
---

diff --git a/lib/zstd.h b/lib/zstd.h
index c19496d02..a84490d99 100644
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -379,9 +379,9 @@ ZSTDLIB_API size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output
 #define ZSTD_WINDOWLOG_MAX_64   31
 #define ZSTD_WINDOWLOG_MAX    ((unsigned)(sizeof(size_t) == 4 ? ZSTD_WINDOWLOG_MAX_32 : ZSTD_WINDOWLOG_MAX_64))
 #define ZSTD_WINDOWLOG_MIN      10
-#define ZSTD_HASHLOG_MAX        MIN(ZSTD_WINDOWLOG_MAX, 30)
+#define ZSTD_HASHLOG_MAX      ((ZSTD_WINDOWLOG_MAX < 30) ? ZSTD_WINDOWLOG_MAX : 30)
 #define ZSTD_HASHLOG_MIN         6
-#define ZSTD_CHAINLOG_MAX       MIN(ZSTD_WINDOWLOG_MAX+1, 30)
+#define ZSTD_CHAINLOG_MAX     ((ZSTD_WINDOWLOG_MAX < 29) ? ZSTD_WINDOWLOG_MAX+1 : 30)
 #define ZSTD_CHAINLOG_MIN       ZSTD_HASHLOG_MIN
 #define ZSTD_HASHLOG3_MAX       17
 #define ZSTD_SEARCHLOG_MAX     (ZSTD_WINDOWLOG_MAX-1)
diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index 141bf6548..13e856be0 100644
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -65,11 +65,18 @@ static UTIL_time_t g_displayClock = UTIL_TIME_INITIALIZER;
             { g_displayClock = UTIL_getTime(); DISPLAY(__VA_ARGS__); \
             if (g_displayLevel>=4) fflush(stderr); } }
 
-/*-*******************************************************
-*  Fuzzer functions
-*********************************************************/
+
 #undef MIN
 #undef MAX
+void FUZ_bug976()
+{   /* these constants shall not depend on MIN() macro */
+    assert(ZSTD_HASHLOG_MAX < 31);
+    assert(ZSTD_CHAINLOG_MAX < 31);
+}
+
+/*-*******************************************************
+*  Internal functions
+*********************************************************/
 #define MIN(a,b) ((a)<(b)?(a):(b))
 #define MAX(a,b) ((a)>(b)?(a):(b))