Invalid parsing with solr edismax operators

[Mahmoud Almokadem <pr...@gmail.com>]

Hello,

I'm using solr 4.8.1. Using edismax as the parser we got the undesirable
parsed queries and results. The following is two different cases with
strange behavior: Searching with these parameters

  "mm":"2",
  "df":"TotalField",
  "debug":"true",
  "indent":"true",
  "fl":"Title",
  "start":"0",
  "q.op":"AND",
  "fq":"",
  "rows":"10",
  "wt":"json"

and the query is

"q":"+(public libraries)",

Retrieve 502 documents with these parsed query

"rawquerystring":"+(public libraries)",
"querystring":"+(public libraries)",
"parsedquery":"(+(+(DisjunctionMaxQuery((Title:public^200.0 |
TotalField:public^0.1)) DisjunctionMaxQuery((Title:libraries^200.0 |
TotalField:libraries^0.1)))))/no_coord",
"parsedquery_toString":"+(+((Title:public^200.0 |
TotalField:public^0.1) (Title:libraries^200.0 |
TotalField:libraries^0.1)))"

and if the query is

"q":" (public libraries) "

then it retrieves 8 documents with these parsed query

"rawquerystring":" (public libraries) ",
"querystring":" (public libraries) ",
"parsedquery":"(+((DisjunctionMaxQuery((Title:public^200.0 |
TotalField:public^0.1)) DisjunctionMaxQuery((Title:libraries^200.0 |
TotalField:libraries^0.1)))~2))/no_coord",
"parsedquery_toString":"+(((Title:public^200.0 |
TotalField:public^0.1) (Title:libraries^200.0 |
TotalField:libraries^0.1))~2)"

So the results of adding "+" to get all tokens before the parenthesis
retrieve more results than removing it.

Is this a bug on this version or there are something missing?