From 9a60e2c532cd1341c2d1dd585c7dcfdc761f2b06 Mon Sep 17 00:00:00 2001
From: ownedbywuigi <ownedbywuigi@gmail.com>
Date: Mon, 30 Mar 2026 11:43:16 +0100
Subject: [PATCH] Update process count preference to a fixed value and enhance
 content parent selection logic

---
 application/basilisk/app/profile/basilisk.js |  6 ++----
 dom/ipc/ContentParent.cpp                    | 15 ++++++++++++++-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/application/basilisk/app/profile/basilisk.js b/application/basilisk/app/profile/basilisk.js
index 1d8b0c6c26..739aa43038 100644
--- a/application/basilisk/app/profile/basilisk.js
+++ b/application/basilisk/app/profile/basilisk.js
@@ -923,10 +923,8 @@ pref("browser.tabs.remote.force-disable", false);
 pref("browser.tabs.remote.desktopbehavior", true);
 pref("browser.tabs.remote.ignoreBlockPolicy", true);
 // Number of web content processes used by e10s.
-// -1 means automatic tab-isolation mode: try one process per tab.
-pref("dom.ipc.processCount", -1);
-// Safety ceiling used by automatic tab-isolation mode.
-pref("dom.ipc.processCount.webIsolatedMax", 64);
+// Keep this at a fixed value in this tree; automatic -1 mode is not supported.
+pref("dom.ipc.processCount", 4);
 
 // This pref governs whether we attempt to work around problems caused by
 // plugins using OS calls to manipulate the cursor while running out-of-
diff --git a/dom/ipc/ContentParent.cpp b/dom/ipc/ContentParent.cpp
index 6dab0bbc82..2d02593dd2 100644
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -602,14 +602,27 @@ ContentParent::GetNewOrUsedBrowserProcess(bool aForBrowserElement,
                                       static_cast<uint32_t>(maxContentParents));
     uint32_t startIdx = rand() % maxSelectable;
     uint32_t currIdx = startIdx;
+    RefPtr<ContentParent> fallback;
     do {
       RefPtr<ContentParent> p = (*contentParents)[currIdx];
-      NS_ASSERTION(p->IsAlive(), "Non-alive contentparent in sBrowserContntParents?");
+      if (!p->IsAlive()) {
+        currIdx = (currIdx + 1) % maxSelectable;
+        continue;
+      }
+
+      if (!fallback) {
+        fallback = p;
+      }
+
       if (p->mOpener == aOpener) {
         return p.forget();
       }
       currIdx = (currIdx + 1) % maxSelectable;
     } while (currIdx != startIdx);
+
+    if (fallback) {
+      return fallback.forget();
+    }
   }
 
   RefPtr<ContentParent> p = new ContentParent(aOpener, aForBrowserElement);