writer: Implement xmlTextWriterClose

This function can be used to make sure that closing the output stream
succeeded.

Fixes #513.

include/libxml/xmlwriter.h

@@ -478,6 +478,7 @@ extern "C" {
  * misc
  */
     XMLPUBFUN int xmlTextWriterFlush(xmlTextWriterPtr writer);
+    XMLPUBFUN int xmlTextWriterClose(xmlTextWriterPtr writer);
 
 #ifdef __cplusplus
 }

testparser.c

@@ -6,6 +6,7 @@
 
 #include <libxml/parser.h>
 #include <libxml/xmlreader.h>
+#include <libxml/xmlwriter.h>
 
 #include <string.h>
 
@@ -203,6 +204,49 @@ testReaderXIncludeError(void) {
 }
 #endif
 
+#ifdef LIBXML_WRITER_ENABLED
+static int
+testWriterIOWrite(void *ctxt, const char *data, int len) {
+    (void) ctxt;
+    (void) data;
+
+    return len;
+}
+
+static int
+testWriterIOClose(void *ctxt) {
+    (void) ctxt;
+
+    return XML_IO_ENAMETOOLONG;
+}
+
+static int
+testWriterClose(void){
+    xmlOutputBufferPtr out;
+    xmlTextWriterPtr writer;
+    int err = 0;
+    int result;
+
+    out = xmlOutputBufferCreateIO(testWriterIOWrite, testWriterIOClose,
+                                  NULL, NULL);
+    writer = xmlNewTextWriter(out);
+    xmlTextWriterStartDocument(writer, "1.0", "UTF-8", NULL);
+    xmlTextWriterStartElement(writer, BAD_CAST "elem");
+    xmlTextWriterEndElement(writer);
+    xmlTextWriterEndDocument(writer);
+    result = xmlTextWriterClose(writer);
+
+    if (result != XML_IO_ENAMETOOLONG) {
+        fprintf(stderr, "xmlTextWriterClose reported wrong error %d\n",
+                result);
+        err = 1;
+    }
+
+    xmlFreeTextWriter(writer);
+    return err;
+}
+#endif
+
 int
 main(void) {
     int err = 0;
@@ -218,6 +262,9 @@ main(void) {
 #if defined(LIBXML_READER_ENABLED) && defined(LIBXML_XINCLUDE_ENABLED)
     err |= testReaderXIncludeError();
 #endif
+#ifdef LIBXML_WRITER_ENABLED
+    err |= testWriterClose();
+#endif
 
     return err;
 }

xmlIO.c

@@ -1508,7 +1508,8 @@ xmlFreeParserInputBuffer(xmlParserInputBufferPtr in) {
  * flushes and close the output I/O channel
  * and free up all the associated resources
  *
- * Returns the number of byte written or -1 in case of error.
+ * Returns the number of byte written or a negative xmlParserErrors
+ * code in case of error.
  */
 int
 xmlOutputBufferClose(xmlOutputBufferPtr out)
@@ -1532,11 +1533,8 @@ xmlOutputBufferClose(xmlOutputBufferPtr out)
         }
     }
 
-    /*
-     * TODO: Report the error code
-     */
     if (out->error != XML_ERR_OK)
-        ret = -1;
+        ret = -out->error;
     else
         ret = out->written;
 

xmlwriter.c

@@ -4236,6 +4236,35 @@ xmlTextWriterFlush(xmlTextWriterPtr writer)
     return count;
 }
 
+/**
+ * xmlTextWriterClose:
+ * @writer:  the xmlTextWriterPtr
+ *
+ * Flushes and closes the output buffer.
+ *
+ * Available since 2.13.0.
+ *
+ * Returns an xmlParserErrors code.
+ */
+int
+xmlTextWriterClose(xmlTextWriterPtr writer)
+{
+    int result;
+
+    if ((writer == NULL) || (writer->out == NULL))
+        return XML_ERR_ARGUMENT;
+
+    result = xmlOutputBufferClose(writer->out);
+    writer->out = NULL;
+
+    if (result >= 0)
+        result = XML_ERR_OK;
+    else
+        result = -result;
+
+    return result;
+}
+
 /**
  * misc
  */