fix docs & add test for discover_datasets sort_by

- order of sort_comp and sort_by was wrong for
  sort_by in collections
- sort_by was missing for data output
- adds a test (though we can't check the generated
  order .. I manually tested with `planemo serve`)

lib/galaxy/tool_util/xsd/galaxy.xsd

@@ -4214,6 +4214,11 @@ More information can be found on Planemo's documentation for
         <xs:documentation xml:lang="en">Format (or datatype) of discovered datasets (an alias with ``format``).</xs:documentation>
       </xs:annotation>
     </xs:attribute>
+    <xs:attribute name="sort_by" type="xs:string" use="optional">
+      <xs:annotation>
+        <xs:documentation xml:lang="en">A string `[reverse_][SORT_COMP_]SORTBY` describing the desired sort order of the collection elements. `SORTBY` can be `filename`, `name`, `designation`, `dbkey` and the optional `SORT_COMP` can be either `lexical` or `numeric`. Default is lexical sorting by filename.</xs:documentation>
+      </xs:annotation>
+    </xs:attribute>
     <xs:attribute name="visible" type="xs:boolean" use="optional">
       <xs:annotation>
         <xs:documentation xml:lang="en">Indication if this dataset is visible in output history. This defaults to ``false``, but probably shouldn't - be sure to set to ``true`` if that is your intention.</xs:documentation>
@@ -4269,7 +4274,7 @@ Galaxy, including:
     </xs:attribute>
     <xs:attribute name="sort_by" type="xs:string" use="optional">
       <xs:annotation>
-        <xs:documentation xml:lang="en">A string `[reverse_]SORTBY[_SORT_COMP]` describing the desired sort order of the collection elements. `SORTBY` can be `filename`, `name`, `designation`, `dbkey` and the optional `SORT_COMP` can be either `lexical` or `numeric`. Default is lexical sorting by filename.</xs:documentation>
+        <xs:documentation xml:lang="en">A string `[reverse_][SORT_COMP_]SORTBY` describing the desired sort order of the collection elements. `SORTBY` can be `filename`, `name`, `designation`, `dbkey` and the optional `SORT_COMP` can be either `lexical` or `numeric`. Default is lexical sorting by filename.</xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="visible" type="xs:boolean" use="optional">

test/functional/tools/discover_sort_by.xml

@@ -0,0 +1,26 @@
+<tool id="collection_split_on_column" name="collection_split_on_column" version="0.1.0">
+  <command>
+    mkdir outputs; cd outputs; awk '{ print \$2 > (\$1 ".tabular") }' $input1
+  </command>
+  <inputs>
+    <param name="input1" type="data" label="Input Table" help="Table to split on first column" format="tabular" />
+  </inputs>
+  <outputs>
+    <collection name="collection_numeric_name" type="list" label="Table split on first column">
+      <discover_datasets pattern="__name_and_ext__" sort_by="numeric_name" directory="outputs" />
+    </collection>
+    <collection name="collection_rev_numeric_name" type="list" label="Table split on first column">
+      <discover_datasets pattern="__name_and_ext__" sort_by="reverse_numeric_name" directory="outputs" />
+    </collection>
+    <data name="data_numeric_name">
+      <discover_datasets pattern="__name_and_ext__" format="tabular" assign_primary_output="true" sort_by="reverse_numeric_name" directory="outputs" visible="true"/>
+    </data>
+  </outputs>
+  <tests>
+    <test>
+      <param name="input1" value="tinywga.fam" />
+      <output_collection name="collection_numeric_name" type="list" count="11"/>
+      <output_collection name="collection_rev_numeric_name" type="list" count="11"/>
+    </test>
+  </tests>
+</tool>

test/functional/tools/samples_tool_conf.xml

@@ -154,6 +154,7 @@
   <tool file="collection_creates_dynamic_nested_fail.xml" />
   <tool file="collection_cat_group_tag.xml" />
   <tool file="collection_cat_group_tag_multiple.xml" />
+  <tool file="discover_sort_by.xml" />
   <tool file="expression_forty_two.xml" />
   <tool file="expression_parse_int.xml" />
   <tool file="expression_log_line_count.xml" />