Something wrong with the parser?

[Ryan Rusaw]

I have a simple tree_walker class that generates xml from the tree,
but it seems like there's an error in the parser where the "column"
value of parsed expressions and statements is off by 1 when there are
preceding comments.
Note: I am using octave hg tip.

octave:7> octave_to_xml ("a.m")
<octave_user_script>
<octave_user_script:body>
<tree_statement_list>
<tree_statement_list:statement>
<tree_statement line="1" column="0" >
<octave_comment_list>
</octave_comment_list>
<tree_statement:expression>
<tree_index_expression line="1" column="0" >
<tree_index_expression:expression>
<tree_identifier line="1" column="0" >
<![CDATA[disp]]>
</tree_identifier>
</tree_index_expression:expression>
<tree_index_expression:paren_arguments>
<tree_argument_list>
<tree_argument_list:argument>
<tree_constant line="1" column="6" >
<![CDATA["hello world"]]>
</tree_constant>
</tree_argument_list:argument>
</tree_argument_list>
</tree_index_expression:paren_arguments>
</tree_index_expression>
</tree_statement:expression>
</tree_statement>
</tree_statement_list:statement>
</tree_statement_list>
</octave_user_script:body>
</octave_user_script>

octave:8> octave_to_xml ("b.m")
<octave_user_script>
<octave_user_script:body>
<tree_statement_list>
<tree_statement_list:statement>
<tree_statement line="2" column="-1" >
<octave_comment_list>
<octave_comment_elt type="0" >
<![CDATA[ comment
]]>
</octave_comment_elt>
</octave_comment_list>
<tree_statement:expression>
<tree_index_expression line="2" column="-1" >
<tree_index_expression:expression>
<tree_identifier line="2" column="-1" >
<![CDATA[disp]]>
</tree_identifier>
</tree_index_expression:expression>
<tree_index_expression:paren_arguments>
<tree_argument_list>
<tree_argument_list:argument>
<tree_constant line="2" column="5" >
<![CDATA["hello world"]]>
</tree_constant>
</tree_argument_list:argument>
</tree_argument_list>
</tree_index_expression:paren_arguments>
</tree_index_expression>
</tree_statement:expression>
</tree_statement>
</tree_statement_list:statement>
</tree_statement_list>
</octave_user_script:body>
</octave_user_script>

Ryan

a.m
Description: Binary data

b.m
Description: Binary data