Fix #78342: Bus error in configure test for iconv //IGNORE

We have to check the return value of iconv_open() for error, to avoid
that and potentially other undesired behavior of iconv().

Author: cmb69

NEWS

@@ -6,6 +6,10 @@ PHP                                                                        NEWS
   . Fixed bug #77946 (Bad cURL resources returned by curl_multi_info_read()).
     (Abyr Valg)
 
+- Iconv:
+  . Fixed bug #78342 (Bus error in configure test for iconv //IGNORE). (Rainer
+    Jung)
+
 - LiteSpeed:
   . Updated to LiteSpeed SAPI V7.5 (Fixed clean shutdown). (George Wang)
 

ext/iconv/config.m4

@@ -166,6 +166,9 @@ int main() {
 
 int main() {
   iconv_t cd = iconv_open( "UTF-8//IGNORE", "UTF-8" );
+  if(cd == (iconv_t)-1) {
+    return 1;
+  }
   char *in_p = "\xC3\xC3\xC3\xB8";
   size_t in_left = 4, out_left = 4096;
   char *out = malloc(out_left);