Avoid uninitialized and unused warnings in contrib/minizip.

contrib/minizip/miniunz.c

@@ -111,6 +111,10 @@ static void change_file_date(const char *filename, uLong dosdate, tm_unz tmu_dat
 
   ut.actime=ut.modtime=mktime(&newdate);
   utime(filename,&ut);
+#else
+  (void)filename;
+  (void)dosdate;
+  (void)tmu_date;
 #endif
 #endif
 }
@@ -127,6 +131,8 @@ static int mymkdir(const char* dirname) {
     ret = mkdir (dirname,0775);
 #elif __APPLE__
     ret = mkdir (dirname,0775);
+#else
+    (void)dirname;
 #endif
     return ret;
 }
@@ -237,7 +243,7 @@ static int do_list(unzFile uf) {
         char filename_inzip[256];
         unz_file_info64 file_info;
         uLong ratio=0;
-        const char *string_method;
+        const char *string_method = "";
         char charCrypt=' ';
         err = unzGetCurrentFileInfo64(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0);
         if (err!=UNZ_OK)

contrib/minizip/minizip.c

@@ -384,7 +384,7 @@ int main(int argc, char *argv[]) {
                    ((argv[i][1]>='0') && (argv[i][1]<='9'))) &&
                   (strlen(argv[i]) == 2)))
             {
-                FILE * fin;
+                FILE * fin = NULL;
                 size_t size_read;
                 const char* filenameinzip = argv[i];
                 const char *savefilenameinzip;