get rid of numerous probably inocuous valgrind/helgrind messages by ensuring that actual string copies are passed between threads, without refcount/shared data magic

src/rcldb/rcldb.cpp

@@ -1419,10 +1419,11 @@ bool Db::addOrUpdate(const string &udi, const string &parent_udi, Doc &doc)
 	// Dates etc.
 	time_t mtime = atoll(doc.dmtime.empty() ? doc.fmtime.c_str() : 
 			     doc.dmtime.c_str());
-	struct tm *tm = localtime(&mtime);
+        struct tm tmb;
+	localtime_r(&mtime, &tmb);
 	char buf[9];
 	snprintf(buf, 9, "%04d%02d%02d",
-		 tm->tm_year+1900, tm->tm_mon + 1, tm->tm_mday);
+		 tmb.tm_year+1900, tmb.tm_mon + 1, tmb.tm_mday);
 	// Date (YYYYMMDD)
 	newdocument.add_boolean_term(wrap_prefix(xapday_prefix) + string(buf)); 
 	// Month (YYYYMM)

src/rcldb/rcldb_p.h

@@ -50,9 +50,11 @@ public:
     // Note that udi and uniterm are strictly equivalent and are
     // passed both just to avoid recomputing uniterm which is
     // available on the caller site.
+    // Take some care to avoid sharing string data (if string impl is cow)
     DbUpdTask(Op _op, const string& ud, const string& un, 
 	      Xapian::Document *d, size_t tl)
-	: op(_op), udi(ud), uniterm(un), doc(d), txtlen(tl)
+	: op(_op), udi(ud.begin(), ud.end()), uniterm(un.begin(), un.end()), 
+          doc(d), txtlen(tl)
     {}
     // Udi and uniterm equivalently designate the doc
     Op op;

src/rcldb/rcldoc.h

@@ -19,12 +19,12 @@
 
 #include <string>
 #include <map>
-
-#ifndef NO_NAMESPACES
 using std::string;
 using std::map;
+
+#include "smallut.h"
+
 namespace Rcl {
-#endif
 
 /**
  * Dumb holder for document attributes and data. 
@@ -139,6 +139,8 @@ class Doc {
 
     void erase() {
 	url.erase();
+        idxurl.erase();
+        idxi = 0;
 	ipath.erase();
 	mimetype.erase();
 	fmtime.erase();
@@ -160,6 +162,30 @@ class Doc {
 	haschildren = false;
 	onlyxattr = false;
     }
+    // Copy ensuring no shared string data, for threading issues.
+    void copyto(Doc *d) const {
+	d->url.assign(url.begin(), url.end());
+        d->idxurl.assign(idxurl.begin(), idxurl.end());
+        d->idxi = idxi;
+	d->ipath.assign(ipath.begin(), ipath.end());
+	d->mimetype.assign(mimetype.begin(), mimetype.end());
+	d->fmtime.assign(fmtime.begin(), fmtime.end());
+	d->dmtime.assign(dmtime.begin(), dmtime.end());
+	d->origcharset.assign(origcharset.begin(), origcharset.end());
+        map_ss_cp_noshr(meta, &d->meta);
+	d->syntabs = syntabs;
+	d->pcbytes.assign(pcbytes.begin(), pcbytes.end());
+	d->fbytes.assign(fbytes.begin(), fbytes.end());
+	d->dbytes.assign(dbytes.begin(), dbytes.end());
+	d->sig.assign(sig.begin(), sig.end());
+        d->text.assign(text.begin(), text.end());
+	d->pc = pc;
+	d->xdocid = xdocid;
+	d->idxi = idxi;
+	d->haspages = haspages;
+	d->haschildren = haschildren;
+	d->onlyxattr = onlyxattr;
+    }
     Doc()
 	: idxi(0), syntabs(false), pc(0), xdocid(0),
 	  haspages(false), haschildren(false), onlyxattr(false)
@@ -247,8 +273,6 @@ class Doc {
 };
 
 
-#ifndef NO_NAMESPACES
 }
-#endif
 
 #endif /* _RCLDOC_H_INCLUDED_ */