meson: Check for shadow password symbols, GitHub #1777

meson.build

@@ -1730,17 +1730,31 @@ endif
 #
 
 enable_shadow = get_option('with-shadow')
-
-if not enable_shadow
-    have_shadow = false
-else
-    have_shadow = (cc.has_header('shadow.h'))
+have_shadow = false
+
+if enable_shadow
+    if cc.has_header('shadow.h')
+        cdata.set('HAVE_SHADOW_H', 1)
+        have_shadow = cc.compiles(
+                '''
+            #include <stdlib.h>
+            #include <stdio.h>
+            #include <shadow.h>
+            int main(void) {
+                struct spwd *sp;
+                getspnam("bork");
+                return 0;
+            }
+            ''',
+            )
+    endif
     if have_shadow
         cdata.set('SHADOWPW', 1)
         uams_options += 'shadow'
     else
         have_shadow = false
-        warning('Shadow password support requested but required header not found')
+        uams_options += 'passwd'
+        warning('Shadow password support requested but required symbols not found')
     endif
 endif