xmerl: Fix XPath substring-before, string-length, sum, round and number()

Author: tomciopp

lib/xmerl/src/xmerl_xpath_pred.erl

@@ -508,8 +508,12 @@ contains(C, [A1, A2]) ->
 'substring-before'(C, [A1, A2]) ->
     S1 = mk_string(C, A1),
     S2 = mk_string(C, A2),
-    Pos = string:str(S1, S2),
-    ?string(string:substr(S1, 1, Pos)).
+    case string:str(S1, S2) of
+	0 ->
+	    ?string([]);
+	Pos ->
+	    ?string(string:substr(S1, 1, Pos - 1))
+    end.
 
 %% string: substring-after(string, string)
 'substring-after'(C, [A1, A2]) ->
@@ -536,10 +540,10 @@ substring(C, [A1, A2, A3]) ->
 
 %% number: string-length(string?)
 'string-length'(C = #xmlContext{context_node = N}, []) ->
-    length(mk_string(C, string_value(N)));
+    ?number(length(mk_string(C, string_value(N))));
 
 'string-length'(C, [A]) ->
-    length(mk_string(C, A)).
+    ?number(length(mk_string(C, A))).
 
 
 %% string: normalize-space(string?)
@@ -633,17 +637,17 @@ match_lang(_, _) ->
 
 %% number: number(object)
 number(C = #xmlContext{context_node = N}, []) ->
-    ?number(mk_number(C, string(C, N)));
+    ?number(mk_number(C, string_value(N)));
 number(C, [Arg]) ->
     ?number(mk_number(C, Arg)).
 
 
 sum(C, [Arg]) ->
     NS = mk_nodeset(C, Arg),
-    lists:foldl(
-      fun(N, Sum) ->
-	      Sum + mk_number(C, string(C, N))
-      end, 0, NS).
+    ?number(lists:foldl(
+	      fun(N, Sum) ->
+		      Sum + mk_number(C, string_value(N))
+	      end, 0, NS)).
 
 floor(C, [Arg]) ->
     Num = mk_number(C, Arg),
@@ -665,14 +669,14 @@ ceiling(C, [Arg]) ->
 
 
 round(C, [Arg]) ->
-    case mk_number(C, Arg) of
+    ?number(case mk_number(C, Arg) of
 	A when is_atom(A) ->
 	    A;
 	N when is_integer(N) ->
 	    N;
 	F when is_float(F) ->
 	    round(F)
-    end.
+    end).
 
 
 select_on_attribute([E = #xmlElement{attributes = Attrs}|T], K, V, Acc) ->

lib/xmerl/test/xmerl_SUITE_data/xpath/xpath_abbrev.erl

@@ -286,6 +286,17 @@ functions() ->
     ok = Test(Doc,"/foo/bar[starts-with(name, 'X')]",[bar,bar]),
     ok = Test(Doc,"/foo/bar[value = string(1)]/value/text()",["1"]),
 
+    %% Regression tests: substring-before used to include the separator's
+    %% first character (off-by-one); string-length and round returned bare
+    %% numbers instead of #xmlObj{type=number}; and sum and number() (no
+    %% args) called string/2 with a bare node, crashing on any non-empty
+    %% node-set.
+    ok = Test(Doc,"/foo/bar[substring-before(name, 'a') = 'Xp']",[bar]),
+    ok = Test(Doc,"/foo/bar[string-length(name) = 3]",[bar]),
+    ok = Test(Doc,"/foo/bar[round(value) = 2]",[bar]),
+    ok = Test(Doc,"/foo[sum(bar/value) = 6]",[foo]),
+    ok = Test(Doc,"/foo/bar/value[number() = 2]",[value]),
+
 
     {Doc2,_}= xmerl_scan:file("purchaseOrder.xml"),
     ok = Test(Doc2,"//*[starts-with(local-name(),'c')]",