bug fix, need va_copy() when reusing a va_list

src/include/ngspice/ngspice.h

@@ -304,4 +304,9 @@ void soa_printf(CKTcircuit *ckt, GENinstance *instance, const char *fmt, ...);
 #define NG_IGNOREABLE(x)  (void)x
 
 
+#if !defined(va_copy) && defined(_MSC_VER)
+#define va_copy(dst, src) ((dst) = (src))
+#endif
+
+
 #endif

src/sharedspice.c

@@ -939,7 +939,11 @@ sh_vfprintf(FILE *f, const char *fmt, va_list args)
     // assert(size > 0);
 
     for (;;) {
-        nchars = vsnprintf(p, size, fmt, args);
+        va_list ap;
+
+        va_copy(ap, args);
+        nchars = vsnprintf(p, size, fmt, ap);
+        va_end(ap);
 
         if(nchars == -1) {           // compatibility to old implementations
             size *= 2;

src/tclspice.c

@@ -2669,7 +2669,11 @@ tcl_vfprintf(FILE *f, const char *fmt, va_list args)
     // assert(size > 0);
 
     for (;;) {
-        nchars = vsnprintf(p + prolog_len, size, fmt, args);
+        va_list ap;
+
+        va_copy(ap, args);
+        nchars = vsnprintf(p + prolog_len, size, fmt, ap);
+        va_end(ap);
 
         if(nchars == -1) {           /* compatibility to old implementations */
             size *= 2;