fix foreach bug : non-prefixed item should not bind to context

[Youmoo]

Here is a demo to reproduce the bug.
Due to the bug, The two following xmls result in different results(which are supposed to be identical):

<select id="flavorOne" resultType="mybatis.TestModal">
        select id,bill_no as billNo from test
        <where>
            <trim suffixOverrides=",">
                <if test="id!=null">
                    id=#{id},
                </if>
                <if test="idList!=null">
                    and id in
                    <foreach collection="idList" item="id" open="(" close=")" separator=",">
                        #{id}
                    </foreach>
                </if>
            </trim>
        </where>
    </select>

vs

    <select id="flavorTwo" resultType="mybatis.TestModal">
        select id,bill_no as billNo from test
        <where>
            <trim suffixOverrides=",">
                <if test="idList!=null">
                    id in
                    <foreach collection="idList" item="id" open="(" close=")" separator=",">
                        #{id}
                    </foreach>
                </if>
                <if test="id!=null">
                    and id=#{id},
                </if>
            </trim>
        </where>
    </select>

[Youmoo]

The Travis CI build failed, but I find the code in org.apache.ibatis.builder.xml.dynamic.DynamicSqlSourceTest#shouldIterateOnceForEachItemInCollection is itself a wrong test case:

        final String expected = "SELECT * FROM BLOG WHERE ID in (  one = ? AND two = ? AND three = ? )";

expected is not valid sql, is it written that way intentionally? Got confused..

[harawata]

Hi,

Thanks for the PR, but the fix breaks existing test cases (five errors were reported other than the failure you pointed out).

Actually, this issue was reported as #49 before.
Please see the @emacarron comment on the ticket.

p.s.
I was wondering how could MyBatis know which 'id' to use when you write #{id} in the foreach loop...
You really should use a unique item variable name, IMHO.

Regards,
Iwao

[Youmoo]

Hi. @harawata I supposed #{id} in the foreach loop to be scoped inside the for loop and should not be accessible outside the for loop.
The document may clarify that accordingly.

[harawata]

PR with documentation changes are also welcome!
The source of the doc is in the following directory in xdoc format.
https://github.com/mybatis/mybatis-3/tree/master/src/site

Note that the PR must includes the English version as we use it for localization.

Regards,
Iwao