Check input of isNumericAddress

app/src/main/java/eu/faircode/email/ConnectionHelper.java

@@ -533,6 +533,9 @@ public class ConnectionHelper {
     }
 
     static boolean isNumericAddress(String host) {
+        // IPv4-mapped IPv6 can be 45 characters
+        if (host == null || host.length() > 64)
+            return false;
         return ConnectionHelper.jni_is_numeric_address(host);
     }
 

app/src/main/jni/fairemail.cc

@@ -13,7 +13,7 @@
 
 void log_android(int prio, const char *fmt, ...) {
     if (prio >= ANDROID_LOG_DEBUG) {
-        char line[4096];
+        char line[1024];
         va_list argptr;
         va_start(argptr, fmt);
         vsprintf(line, fmt, argptr);