package com.acme.jira.web;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.IOException;

/**
 * This filter fixed error
 * http://jira.atlassian.com/browse/JRA-13791
 *
 * @author Alexey Efimov
 */
public class SafariLeopardBugFixFilter implements Filter {
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (servletRequest instanceof HttpServletRequest) {
            HttpServletRequest request = (HttpServletRequest) servletRequest;
            String userAgent = request.getHeader("USER-AGENT");
            // For Safari on Leopard it is:
            // Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-us) AppleWebKit/523.10.3 (KHTML, like Gecko) Version/3.0.4 Safari/523.10
            if (userAgent != null && userAgent.indexOf("Safari") > 0 && userAgent.indexOf("Version/3.0.4") > 0) {
                String type = request.getContentType();
                if ("GET".equals(request.getMethod()) &&
                        type != null && type.startsWith("multipart/form-data")) {
                    servletRequest = toNullableContentTypeRequest(request);
                }
            }
        }
        filterChain.doFilter(servletRequest, servletResponse);
    }

    private HttpServletRequest toNullableContentTypeRequest(HttpServletRequest delegate) {
        return new NullableContentTypeHttpServletRequest(delegate);
    }

    public void destroy() {
    }

    private static class NullableContentTypeHttpServletRequest extends HttpServletRequestWrapper {
        public NullableContentTypeHttpServletRequest(HttpServletRequest delegate) {
            super(delegate);
        }

        public String getHeader(String s) {
            if ("Content-Type".equalsIgnoreCase(s)) {
                return null;
            }
            return super.getHeader(s);
        }

        public String getContentType() {
            return null;
        }
    }
}

...
    <!-- Fix for Safari 3.0.4 -->
    <filter>
        <filter-name>SafariLeopard</filter-name>
        <filter-class>com.acme.jira.web.SafariLeopardBugFixFilter</filter-class>
    </filter>
...
    <filter-mapping>
        <filter-name>SafariLeopard</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
...

package com.acme.jira.web;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.IOException;

/**
 * This filter fixed error
 * http://jira.atlassian.com/browse/JRA-13791
 *
 * @author Alexey Efimov
 */
public class SafariLeopardBugFixFilter implements Filter {
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (servletRequest instanceof HttpServletRequest) {
            HttpServletRequest request = (HttpServletRequest) servletRequest;
            String userAgent = request.getHeader("USER-AGENT");
            // For Safari on Leopard it is:
            // Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-us) AppleWebKit/523.10.3 (KHTML, like Gecko) Version/3.0.4 Safari/523.10
            // or
            // Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_2; en-us) AppleWebKit/525.13 (KHTML, like Gecko) Version/3.1 Safari/525.13
            if (userAgent != null && userAgent.indexOf("Safari") > 0) {
                String type = request.getContentType();
                if ("GET".equals(request.getMethod()) &&
                        type != null && type.startsWith("multipart/form-data")) {
                    servletRequest = toNullableContentTypeRequest(request);
                }
            }
        }
        filterChain.doFilter(servletRequest, servletResponse);
    }

    private HttpServletRequest toNullableContentTypeRequest(HttpServletRequest delegate) {
        return new NullableContentTypeHttpServletRequest(delegate);
    }

    public void destroy() {
    }

    private static class NullableContentTypeHttpServletRequest extends HttpServletRequestWrapper {
        public NullableContentTypeHttpServletRequest(HttpServletRequest delegate) {
            super(delegate);
        }

        public String getHeader(String s) {
            if ("Content-Type".equalsIgnoreCase(s)) {
                return null;
            }
            return super.getHeader(s);
        }

        public String getContentType() {
            return null;
        }
    }
}