added gzip tests

also : made sure zstd --format=gzip -V
would fail if gzip compatibility is not supported

programs/bench.c

@@ -581,6 +581,7 @@ int BMK_benchFiles(const char** fileNamesTable, unsigned nbFiles, const char* di
 {
     double const compressibility = (double)g_compressibilityDefault / 100;
 
+    if (cLevel < 1) cLevel = 1;   /* minimum compression level */
     if (cLevel > ZSTD_maxCLevel()) cLevel = ZSTD_maxCLevel();
     if (cLevelLast > ZSTD_maxCLevel()) cLevelLast = ZSTD_maxCLevel();
     if (cLevelLast < cLevel) cLevelLast = cLevel;

programs/zstdcli.c

@@ -370,10 +370,12 @@ int main(int argCount, const char* argv[])
                     if (!strcmp(argument, "--keep")) { FIO_setRemoveSrcFile(0); continue; }
                     if (!strcmp(argument, "--rm")) { FIO_setRemoveSrcFile(1); continue; }
                     if (!strcmp(argument, "--priority=rt")) { setRealTimePrio = 1; continue; }
+#ifdef ZSTD_GZCOMPRESS
                     if (!strcmp(argument, "--format=gzip")) { suffix = GZ_EXTENSION; FIO_setCompressionType(FIO_gzipCompression); continue; }
+#endif
 
                     /* long commands with arguments */
-#ifndef  ZSTD_NODICT
+#ifndef ZSTD_NODICT
                     if (longCommandWArg(&argument, "--cover=")) {
                       cover=1; if (!parseCoverParameters(argument, &coverParams)) CLEAN_RETURN(badusage(programName));
                       continue;