[evince/wip/chpe/xmp: 21/29] libdocument: Only register XML namespaces once

[Germán Poo-Caamaño <gpoo src gnome org>]

commit e3d2e6dc4298dabe4b3c8e513b8891e1e43169a0
Author: Christian Persch <chpe src gnome org>
Date:   Sat Dec 4 01:45:44 2021 +0100

    libdocument: Only register XML namespaces once

 libdocument/ev-xmp.c | 48 +++++++++++++++++++-----------------------------
 1 file changed, 19 insertions(+), 29 deletions(-)
---
diff --git a/libdocument/ev-xmp.c b/libdocument/ev-xmp.c
index 20d5cfd79..645a1b6e0 100644
--- a/libdocument/ev-xmp.c
+++ b/libdocument/ev-xmp.c
@@ -77,19 +77,6 @@ xmp_get_tag_from_xpath (xmlXPathContextPtr xpathCtx,
 
         xmpmetapath = g_strdup_printf ("%s%s", "/x:xmpmeta", xpath);
 
-        /* add pdf/a and pdf/x namespaces */
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "x", BAD_CAST "adobe:ns:meta/");
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "rdf", BAD_CAST 
"http://www.w3.org/1999/02/22-rdf-syntax-ns#";);
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdfaid", BAD_CAST "http://www.aiim.org/pdfa/ns/id/";);
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdfxid", BAD_CAST "http://www.npes.org/pdfx/ns/id/";);
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdfx", BAD_CAST "http://ns.adobe.com/pdfx/1.3/";);
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdf", BAD_CAST "http://ns.adobe.com/pdf/1.3/";);
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "xmp", BAD_CAST "http://ns.adobe.com/xap/1.0/";);
-        /* XMP Rights Management Schema */
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "xmpRights", BAD_CAST "http://ns.adobe.com/xap/1.0/rights/";);
-        /* Creative Commons Schema */
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "cc", BAD_CAST "http://creativecommons.org/ns#";);
-
         /* Try in /rdf:RDF/ */
         xpathObj = xmlXPathEvalExpression (BAD_CAST xpath, xpathCtx);
         if (xpathObj == NULL)
@@ -176,7 +163,7 @@ xmp_get_pdf_format (xmlXPathContextPtr xpathCtx)
 
 static char *
 xmp_get_lists_from_dc_tags (xmlXPathContextPtr xpathCtx,
-                                     const char* xpath)
+                            const char* xpath)
 {
         xmlXPathObjectPtr xpathObj;
         int i;
@@ -185,11 +172,6 @@ xmp_get_lists_from_dc_tags (xmlXPathContextPtr xpathCtx,
         char* result = NULL;
         xmlChar* content;
 
-        /* add xmp namespaces */
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "x", BAD_CAST "adobe:ns:meta/");
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "rdf", BAD_CAST 
"http://www.w3.org/1999/02/22-rdf-syntax-ns#";);
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "dc", BAD_CAST "http://purl.org/dc/elements/1.1/";);
-
         /* reads pdf/a sequence*/
         xpathObj = xmlXPathEvalExpression (BAD_CAST xpath, xpathCtx);
         if (xpathObj == NULL)
@@ -278,15 +260,6 @@ xmp_get_localized_object_from_xpath_format (xmlXPathContextPtr xpathCtx,
         int i, j;
         char *loc_object= NULL;
 
-        /* register namespaces */
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "x", BAD_CAST "adobe:ns:meta/");
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "rdf", BAD_CAST 
"http://www.w3.org/1999/02/22-rdf-syntax-ns#";);
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "dc", BAD_CAST "http://purl.org/dc/elements/1.1/";);
-        /* XMP Rights Management Schema */
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "xmpRights", BAD_CAST "http://ns.adobe.com/xap/1.0/rights/";);
-        /* Creative Commons Schema */
-        xmlXPathRegisterNs (xpathCtx, BAD_CAST "cc", BAD_CAST "http://creativecommons.org/ns#";);
-
         /* 1) checking for a suitable localized string */
         language_string = pango_language_to_string (pango_language_get_default ());
         tags = g_strsplit (language_string, "-", -1);
@@ -423,7 +396,24 @@ ev_xmp_parse (const gchar    *metadata,
                 return FALSE; /* invalid xpath context */
         }
 
-        /* reads pdf metadata date */
+        /* Register namespaces */
+        /* XMP */
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "dc", BAD_CAST "http://purl.org/dc/elements/1.1/";);
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "x", BAD_CAST "adobe:ns:meta/");
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "xmp", BAD_CAST "http://ns.adobe.com/xap/1.0/";);
+        /* XMP Rights Management Schema */
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "xmpRights", BAD_CAST "http://ns.adobe.com/xap/1.0/rights/";);
+        /* RDF */
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "rdf", BAD_CAST 
"http://www.w3.org/1999/02/22-rdf-syntax-ns#";);
+        /* PDF/A and PDF/X namespaces */
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdf", BAD_CAST "http://ns.adobe.com/pdf/1.3/";);
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdfaid", BAD_CAST "http://www.aiim.org/pdfa/ns/id/";);
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdfx", BAD_CAST "http://ns.adobe.com/pdfx/1.3/";);
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "pdfxid", BAD_CAST "http://www.npes.org/pdfx/ns/id/";);
+        /* Creative Commons Schema */
+        xmlXPathRegisterNs (xpathCtx, BAD_CAST "cc", BAD_CAST "http://creativecommons.org/ns#";);
+
+        /* Read metadata date */
         metadata_date = (gchar *)xmp_get_tag_from_xpath (xpathCtx, META_DATE);
         if (metadata_date != NULL) {
                 metadata_datetime = g_date_time_new_from_iso8601 (metadata_date, NULL);