pf: Make Firefox form padding consistent with other browsers

It seems Firefox fixed their longstanding bug, which caused the
workaround in PatternFly (who adopted it from us) to no longer be
relevant. I adjusted our own workaround, but it didn't apply as
PatternFly also (at some point in time) changed the DOM so the selector
no longer matched.

We'll want to communicate this with PF to get PF6 fixed. Possibly even
PF5 too, as it apparently changed in Firefox recently, and therefore
newer versions of Firefox will "break" the expected layout without
addressing it in PF directly (or with a workaround in codebases).

Meanwhile, overriding the override by setting the left spacing to be the
standard left spacing makes sense too. And we can just set this for
Firefox-only instead of everything (which would still work, of course,
but let's scope this to the scope of the issue related to the
workaround).

Fixes #21671
https://issues.redhat.com/browse/RHEL-12150

pkg/lib/patternfly/patternfly-5-overrides.scss

@@ -53,19 +53,21 @@ to wrap around when there isn't enough space.
   overflow-y: auto;
 }
 
-/* Adjust padding on form selects to resemble PF non-form selects */
-/* (This can be seen when the longest text is selected on a non-stretched select) */
-/* Upstream: https://github.com/patternfly/patternfly/issues/4387 */
-/* Cockpit-Podman: https://github.com/cockpit-project/cockpit-podman/issues/755 */
-select.pf-v5-c-form-control {
-  --pf-v5-c-form-control--PaddingRight: 41px;
-  --pf-v5-c-form-control--PaddingLeft: 8px;
-
-  // Firefox's select text has additional padding (4px)
-  /* stylelint-disable-next-line at-rule-no-vendor-prefix */
-  @-moz-document url-prefix() {
-    --pf-v5-c-form-control--PaddingRight: 37px;
-    --pf-v5-c-form-control--PaddingLeft: 4px;
+/* New issue based on the regression based on workaround causing this issue: https://github.com/cockpit-project/cockpit/issues/21671
+*/
+/* Old upstream: https://github.com/patternfly/patternfly/issues/4387 */
+/* Old Cockpit-Podman: https://github.com/cockpit-project/cockpit-podman/issues/755 */
+.pf-v5-c-form-control > select {
+  /* Right side needs to compensate for the icon and space around it,
+  for all browsers */
+  --pf-v5-c-form-control--PaddingRight: calc(
+    var(--pf-v5-global--icon--FontSize--md) + var(--pf-v5-global--spacer--lg)
+  );
+
+  @-moz-document url-prefix() { // stylelint-disable-line at-rule-no-vendor-prefix
+    /* "Unset" Firefox special handling in PatternFly; using consistent
+    spacing with others; this can be removed after PatternFly removes it */
+    --pf-v5-c-form-control--PaddingLeft: var(--pf-v5-c-form-control--inset--base);
   }
 }