Portability fix

src/main.c

@@ -32,6 +32,7 @@
 #include <string.h>
 #include <libxml/tree.h>
 #include <err.h>
+#include <time.h>
 #include "meta.h"
 #include "odt.h"
 #include "options.h"
@@ -101,11 +102,13 @@ int main(int argc, char* argv[]) {
             xmlChar* doc;
             char templateFileName[FILENAME_MAX];
             char timestamp[20];
-            time_t tm;
+            time_t t;
+            struct tm ts;
 
             /* get timestamp */
-            time(&tm);
-            strftime(timestamp, 20, "%Y-%m-%dT%H:%M:%S", localtime(&tm));
+            time(&t);
+            localtime_r(&t, &ts);
+            strftime(timestamp, 20, "%Y-%m-%dT%H:%M:%S", &ts);
 
             xmlDocDumpMemoryEnc(transformed, &doc, &sz, "utf-8");
             entry[0].path = "content.xml";