p2D: respect preset plot limits

pub/lib/plot.cpp

@@ -542,11 +542,14 @@ namespace {
             yinf = std::min(yinf, yyinf);
             ysup = std::max(ysup, yysup);
         }
-        plot->X.set_limits(xinf, xsup);
-        plot->Z.set_limits(zlim.front(), zlim.back());
+        if (!plot->X.finite())
+            plot->X.set_limits(xinf, xsup);
+        if (!plot->Z.finite())
+            plot->Z.set_limits(zlim.front(), zlim.back());
         if (plot->Y.logflag && !(std::isfinite(yinf) && std::isfinite(ysup)))
             throw "No nonzero y values";
-        plot->Y.set_limits(yinf, ysup);
+        if (!plot->Y.finite())
+            plot->Y.set_limits(yinf, ysup);
         // plot
         plot->start_frame2D("Frida version " VERSION);
         for (size_t j=0; j<m; ++j) {