From 61cfbf1578622980d96d5f7e9269a6ac092490d7 Mon Sep 17 00:00:00 2001
From: h7x4 <h7x4@nani.wtf>
Date: Mon, 30 Sep 2024 17:24:29 +0200
Subject: [PATCH 1/2] lib: let `getAttrs` ignore nonexistent keys

Like its cousin `lib.removeAttrs`, `getAttrs` should now ignore keys
that does not exist in the attrset.
---
 lib/attrsets.nix | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/attrsets.nix b/lib/attrsets.nix
index 8bb4ef972fd8c..8668be1892794 100644
--- a/lib/attrsets.nix
+++ b/lib/attrsets.nix
@@ -541,7 +541,8 @@ rec {
 
   /**
     Given a set of attribute names, return the set of the corresponding
-    attributes from the given set.
+    attributes from the given set. If the attributes does not exist,
+    they will be ignored.
 
 
     # Inputs
@@ -565,7 +566,7 @@ rec {
     ## `lib.attrsets.getAttrs` usage example
 
     ```nix
-    getAttrs [ "a" "b" ] { a = 1; b = 2; c = 3; }
+    getAttrs [ "a" "b" "d" ] { a = 1; b = 2; c = 3; }
     => { a = 1; b = 2; }
     ```
 
@@ -573,7 +574,7 @@ rec {
   */
   getAttrs =
     names:
-    attrs: genAttrs names (name: attrs.${name});
+    attrs: intersectAttrs (genAttrs names (_: null)) attrs;
 
   /**
     Collect each attribute named `attr` from a list of attribute

From d243c48b1412e86bb1589b6064ba8d4638129ca7 Mon Sep 17 00:00:00 2001
From: h7x4 <h7x4@nani.wtf>
Date: Mon, 30 Sep 2024 17:26:30 +0200
Subject: [PATCH 2/2] lib/tests: test `getAttrs`

---
 lib/tests/misc.nix | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/tests/misc.nix b/lib/tests/misc.nix
index 116d86cdfb3fb..17617171bec1b 100644
--- a/lib/tests/misc.nix
+++ b/lib/tests/misc.nix
@@ -57,6 +57,7 @@ let
     functionArgs
     generators
     genList
+    getAttrs
     getExe
     getExe'
     getLicenseFromSpdxIdOr
@@ -2094,6 +2095,18 @@ runTests {
     };
   };
 
+  testGetAttrs = {
+    expr = getAttrs [ "a" "b" "nonexistent" ] {
+      a = 1;
+      b = true;
+      c = "hello";
+    };
+    expected = {
+      a = 1;
+      b = true;
+    };
+  };
+
   ## Levenshtein distance functions and co.
   testCommonPrefixLengthEmpty = {
     expr = strings.commonPrefixLength "" "hello";