[libgsf] xml: provide a way to shut up complaints about unknown tags.

[Morten Welinder <mortenw src gnome org>]

commit f66c8fb1e3fa18885779e44e85e45c455312b59b
Author: Morten Welinder <terra gnome org>
Date:   Fri Mar 13 21:33:34 2015 -0400

    xml: provide a way to shut up complaints about unknown tags.
    
    xlsx has <extLst> which, by definition, contains extensions to the
    format we cannot known about in advance.

 ChangeLog        |    4 ++++
 NEWS             |    1 +
 gsf/gsf-libxml.c |   22 +++++++++++++++++++++-
 gsf/gsf-libxml.h |    1 +
 4 files changed, 27 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 3d43a1e..5cedf27 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2015-03-13  Morten Welinder  <terra gnome org>
+
+       * gsf/gsf-libxml.c (gsf_xml_in_set_silent_unknowns): New function.
+
 2015-03-04  Morten Welinder  <terra gnome org>
 
        * gsf/gsf-libxml.c (gsf_xml_out_add_float): Do a better job of
diff --git a/NEWS b/NEWS
index 3bd40a7..1a15e3d 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,7 @@ libgsf 1.14.33
 
 Morten:
        * Ensure floats roundtrip through our xml functions.
+       * Improve handling of unknown xml tags.
 
 --------------------------------------------------------------------------
 libgsf 1.14.32
diff --git a/gsf/gsf-libxml.c b/gsf/gsf-libxml.c
index 7097fa9..e5365ab 100644
--- a/gsf/gsf-libxml.c
+++ b/gsf/gsf-libxml.c
@@ -591,6 +591,7 @@ typedef struct {
        gint              unknown_depth; /* handle recursive unknown tags */
        gboolean          from_unknown_handler;
        gboolean          debug_parsing;
+       gboolean          silent_unknowns;
 
        GSList           *extension_stack; /* stack of GsfXMLInExtension */
 } GsfXMLInInternal;
@@ -725,7 +726,7 @@ gsf_xml_in_start_element (GsfXMLInInternal *state, xmlChar const *name, xmlChar
        GSList *ptr;
        char const *tmp;
        int i;
-       gboolean complain = TRUE;
+       gboolean complain = !state->silent_unknowns;
 
        /* Scan for namespace declarations.  Yes it is ugly to have the api
         * flag that its children can declare namespaces. However, given that a
@@ -957,6 +958,7 @@ gsf_xml_in_start_document (GsfXMLInInternal *state)
        state->contents_stack   = NULL;
        state->from_unknown_handler = FALSE;
        state->debug_parsing = gsf_debug_flag ("xml-parsing");
+       state->silent_unknowns = FALSE;
 }
 
 static void
@@ -1361,6 +1363,24 @@ gsf_xml_in_get_input (GsfXMLIn const *xin)
 }
 
 /**
+ * gsf_xml_in_set_silent_unknowns:
+ * @xin: #GsfXMLIn
+ * @silent: whether to be silent about unknown tags
+ *
+ * (New in 1.14.33)
+ *
+ * This provides a means to silently ignore unknown tags in contexts where
+ * they are expected.
+ **/
+void
+gsf_xml_in_set_silent_unknowns (GsfXMLIn *xin, gboolean silent)
+{
+       GsfXMLInInternal *state = (GsfXMLInInternal *)xin;
+       state->silent_unknowns = silent;
+}
+
+
+/**
  * gsf_xml_in_check_ns:
  * @xin: #GsfXMLIn
  * @str: string to check
diff --git a/gsf/gsf-libxml.h b/gsf/gsf-libxml.h
index bfe2812..9686716 100644
--- a/gsf/gsf-libxml.h
+++ b/gsf/gsf-libxml.h
@@ -143,6 +143,7 @@ char const  *gsf_xml_in_check_ns   (GsfXMLIn const *xin, char const *str,
                                    unsigned int ns_id);
 gboolean     gsf_xml_in_namecmp           (GsfXMLIn const *xin, char const *str,
                                    unsigned int ns_id, char const *name);
+void         gsf_xml_in_set_silent_unknowns (GsfXMLIn *xin, gboolean silent);
 
 GType       gsf_xml_in_ns_get_type (void);