The R Project SVN – R – Diff – /trunk/src/main/plot.c

 	if (length(spec) == 0) {
 	    *ptxt = R_NilValue;
+	}
 	else {
 	    nms = getAttrib(spec, R_NamesSymbol);
+	    if (nms==R_NilValue){ /* PR#1939 */
+	       txt = VECTOR_ELT(spec, 0);
+	       if (TYPEOF(txt) == LANGSXP ||TYPEOF(txt) == SYMSXP ) {
+		    UNPROTECT(1);
+		    PROTECT(txt = coerceVector(txt, EXPRSXP));
+	       }
+	       else if (!isExpression(txt)) {
+		    UNPROTECT(1);
+		    PROTECT(txt = coerceVector(txt, STRSXP));
+	       }
+	    } else {
-	    n = length(nms);
+	       n = length(nms);
-	    for (i = 0; i < n; i++) {
+	       for (i = 0; i < n; i++) {
 		if (!strcmp(CHAR(STRING_ELT(nms, i)), "cex")) {
 		    cex = asReal(VECTOR_ELT(spec, i));
+		}
 		else if (!strcmp(CHAR(STRING_ELT(nms, i)), "col")) {
 		    col = asInteger(FixupCol(VECTOR_ELT(spec, i), NA_INTEGER));
 			UNPROTECT(1);
 			PROTECT(txt = coerceVector(txt, STRSXP));
+		    }
+		}
 		else errorcall(call, "invalid graphics parameter");
+	       }
+	    }
+	}
 	break;
     case STRSXP:
     case EXPRSXP:

The R Project SVN R