Output should not include extraneous newlines when indent is off

Hence matching behaviour of xmlSaveOption XML_SAVE_FORMAT off.
This affects only one of the regression tests

libxslt/xsltutils.c

@@ -1587,5 +1587,5 @@
 	    while (child != NULL) {
 		xmlNodeDumpOutput(buf, result, child, 0, (indent == 1),
 			          (const char *) encoding);
-		if ((child->type == XML_DTD_NODE) ||
+		if (indent && ((child->type == XML_DTD_NODE) ||
 		    ((child->type == XML_COMMENT_NODE) &&
@@ -1591,5 +1591,5 @@
 		    ((child->type == XML_COMMENT_NODE) &&
-		     (child->next != NULL)))
+		     (child->next != NULL))))
 		    xmlOutputBufferWriteString(buf, "\n");
 		child = child->next;
 	    }
@@ -1593,6 +1593,7 @@
 		    xmlOutputBufferWriteString(buf, "\n");
 		child = child->next;
 	    }
+	    if (indent)
 			xmlOutputBufferWriteString(buf, "\n");
 	}
 	xmlOutputBufferFlush(buf);

tests/docs/bug-173.xml

+<root/>

tests/general/Makefile.am

@@ -180,6 +180,7 @@
     bug-170.out bug-170.xsl \
     bug-171.out bug-171.xsl \
     bug-172.out bug-172.xsl \
+    bug-173.out bug-173.xsl \
     character.out character.xsl \
     character2.out character2.xsl \
     itemschoose.out itemschoose.xsl \

tests/general/bug-173.out

+<!--Comment--><root/>
\ No newline at end of file

tests/general/bug-173.xsl

+<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+
+<xsl:output indent="no" omit-xml-declaration="yes"/>
+
+<xsl:template match="/">
+  <!-- Output should not include extraneous newlines when indent is off -->
+  <xsl:comment>Comment</xsl:comment>
+  <root/>
+</xsl:template>
+
+</xsl:stylesheet>
\ No newline at end of file

tests/keys/month.out

@@ -4,4 +4,4 @@
   <month>December</month>
   <month>December</month>
   <month/>
-</dates>
+</dates>
\ No newline at end of file