Vendor in a purple-sys wrapper

This code comes from https://github.com/Flared/purple-icq/tree/master/src/purple

It is GPL-3 licensed

src/purple/blist.rs

@@ -0,0 +1,45 @@
+use super::ffi::AsPtr;
+use libc::c_char;
+use std::ffi::CStr;
+use std::ffi::CString;
+use std::ptr::NonNull;
+
+pub struct BlistNode(NonNull<purple_sys::PurpleBlistNode>);
+
+impl BlistNode {
+    pub unsafe fn from_ptr(ptr: *mut purple_sys::PurpleBlistNode) -> Option<Self> {
+        NonNull::new(ptr).map(Self)
+    }
+
+    pub fn get_string(&mut self, key: &str) -> Option<&str> {
+        let c_key = CString::new(key).unwrap();
+
+        unsafe {
+            let c_value = purple_sys::purple_blist_node_get_string(self.0.as_ptr(), c_key.as_ptr());
+            NonNull::new(c_value as *mut c_char).map(|p| {
+                CStr::from_ptr(p.as_ptr() as *const c_char)
+                    .to_str()
+                    .unwrap()
+            })
+        }
+    }
+
+    pub fn set_string(&mut self, key: &str, value: &str) {
+        let c_key = CString::new(key).unwrap();
+        let c_value = CString::new(value).unwrap();
+        unsafe {
+            purple_sys::purple_blist_node_set_string(
+                self.0.as_ptr(),
+                c_key.as_ptr(),
+                c_value.as_ptr(),
+            );
+        }
+    }
+}
+
+impl AsPtr for BlistNode {
+    type PtrType = purple_sys::PurpleBlistNode;
+    fn as_ptr(&self) -> *const Self::PtrType {
+        self.0.as_ptr()
+    }
+}