#6181 Drop redundantGetAndSetUserId. Ensure (style-) warnings are issued if setuid()/getuid() and some related functions are ignored. Move strdupa()/strndupa() from posix.cfg to gnu.cfg

test/cfg/gnu.c

@@ -0,0 +1,22 @@
+
+// Test library configuration for gnu.cfg
+//
+// Usage:
+// $ cppcheck --check-library --library=gnu --enable=information --enable=style --error-exitcode=1 --inline-suppr test/cfg/gnu.c
+// =>
+// No warnings about bad library configuration, unmatched suppressions, etc. exitcode=0
+//
+
+#include <string.h>
+#include <unistd.h>
+
+void leakReturnValNotUsed() {
+   // cppcheck-suppress unreadVariable
+   char* ptr = strdupa("test");
+   // cppcheck-suppress ignoredReturnValue
+   strdupa("test");
+   // cppcheck-suppress unreadVariable
+   char* ptr2 = strndupa("test", 1);
+   // cppcheck-suppress ignoredReturnValue
+   strndupa("test", 1);
+}