Borrowed from Debian.

--- swish-e-2.4.7/src/parser.c	2009-04-05 03:58:32.000000000 +0200
+++ swish-e-2.4.7/src/parser.c	2013-06-11 13:53:08.196559035 +0200
@@ -1760,7 +1760,7 @@
     va_start(args, msg);
     vsnprintf(str, 1000, msg, args );
     va_end(args);
-    xmlParserError(parse_data->ctxt, str);
+    xmlParserError(parse_data->ctxt, "%s", str);
 }
 
 static void warning(void *data, const char *msg, ...)
@@ -1772,7 +1772,7 @@
     va_start(args, msg);
     vsnprintf(str, 1000, msg, args );
     va_end(args);
-    xmlParserWarning(parse_data->ctxt, str);
+    xmlParserWarning(parse_data->ctxt, "%s", str);
 }
 
 
--- swish-e-2.4.7/src/result_output.c	2009-04-05 03:58:32.000000000 +0200
+++ swish-e-2.4.7/src/result_output.c	2013-06-11 13:53:38.593550825 +0200
@@ -752,7 +752,7 @@
             s = (char *) emalloc(MAXWORDLEN + 1);
             n = strftime(s, (size_t) MAXWORDLEN, fmt, localtime(&(pv->value.v_date)));
             if (n && f)
-                fprintf(f, s);
+                fprintf(f, "%s", s);
             efree(s);
         }
         break;
uix/'>summary</a><a href='/guix/refs/?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>refs</a><a class='active' href='/guix/log/gnu/installer/substitutes.scm'>log</a><a href='/guix/tree/gnu/installer/substitutes.scm?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>tree</a><a href='/guix/commit/gnu/installer/substitutes.scm?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>commit</a><a href='/guix/diff/gnu/installer/substitutes.scm?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/installer/substitutes.scm'>
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<div class='path'>path: <a href='/guix/log/?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>root</a>/<a href='/guix/log/gnu?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>gnu</a>/<a href='/guix/log/gnu/installer?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>installer</a>/<a href='/guix/log/gnu/installer/substitutes.scm?id=dc87d7608701c85e8274197f85d3739c11b98a6b'>substitutes.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/installer/substitutes.scm?id=dc87d7608701c85e8274197f85d3739c11b98a6b&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-12-11 21:37:07 +0100'>2020-12-11</span></td><td><a href='/guix/commit/gnu/installer/substitutes.scm?id=8361817bf693742757b096468198626f297bb09e'>install: Discover local substitute servers.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/substitutes.scm: New file.
* gnu/installer/newt/substitutes.scm: New file.
* gnu/local.mk (INSTALLER_MODULES): Add them.
* po/guix/POTFILES.in: Add gnu/installer/newt/substitutes.scm.
* gnu/installer/proxy.scm (with-silent-shepherd): Move to ...
* gnu/installer/utils.scm: ... here.
* gnu/installer/record.scm (&lt;installer&gt;)[substitutes-page]: New field.
* gnu/installer/newt.scm (substitutes-page): New procedure,
(newt-installer): register it.
* gnu/installer.scm (installer-steps): Add "substitutes-page" step.
* gnu/system/install.scm (%installation-services): Add avahi-service-type and
enable substitute server discover in guix-service-type.
[&lt;name-service-switch&gt;]: Set it to %mdns-host-lookup-nss.
</span></span></td><td>Mathieu Othacehe</td></tr>