Bug 1880368 - change firefox and firefox-private protocols to firefox-bridge and firefox-private-bridge protocols r=nshukla,mossop

Differential Revision: https://phabricator.services.mozilla.com/D201879

browser/app/macbuild/Contents/Info.plist.in

@@ -237,7 +237,7 @@
 			<string>Firefox Protocol</string>
 			<key>CFBundleURLSchemes</key>
 			<array>
-				<string>firefox</string>
+				<string>firefox-bridge</string>
 			</array>
 		</dict>
 		<dict>
@@ -245,7 +245,7 @@
 			<string>Firefox Private Browsing Protocol</string>
 			<key>CFBundleURLSchemes</key>
 			<array>
-				<string>firefox-private</string>
+				<string>firefox-private-bridge</string>
 			</array>
 		</dict>
 	</array>

browser/app/profile/firefox.js

@@ -298,9 +298,6 @@ pref("browser.shell.checkDefaultPDF.silencedByUser", false);
 // URL to navigate to when launching Firefox after accepting the Windows Default
 // Browser Agent "Set Firefox as default" call to action.
 pref("browser.shell.defaultBrowserAgent.thanksURL", "https://www.mozilla.org/%LOCALE%/firefox/set-as-default/thanks/");
-// Whether or not we want to run through the early startup idle task
-// which registers the firefox and firefox-private registry keys.
-pref("browser.shell.customProtocolsRegistered", false);
 #endif
 
 

browser/components/BrowserContentHandler.sys.mjs

@@ -90,7 +90,7 @@ function resolveURIInternal(
     if (aArgument.startsWith(protocolWithColon)) {
       if (!validateFirefoxProtocol(aCmdLine, launchedWithArg_osint)) {
         throw new Error(
-          "Invalid use of Firefox and Firefox-private protocols."
+          "Invalid use of Firefox-bridge and Firefox-private-bridge protocols."
         );
       }
       aArgument = aArgument.substring(protocolWithColon.length);
@@ -100,7 +100,7 @@ function resolveURIInternal(
         !aArgument.startsWith("https://")
       ) {
         throw new Error(
-          "Firefox and Firefox-private protocols can only be used in conjunction with http and https urls."
+          "Firefox-bridge and Firefox-private-bridge protocols can only be used in conjunction with http and https urls."
         );
       }
 
@@ -113,8 +113,8 @@ function resolveURIInternal(
     }
   };
 
-  handleFirefoxProtocol("firefox");
+  handleFirefoxProtocol("firefox-bridge");
-  handleFirefoxProtocol("firefox-private");
+  handleFirefoxProtocol("firefox-private-bridge");
 
   var uri = aCmdLine.resolveURI(aArgument);
   var uriFixup = Services.uriFixup;
@@ -599,7 +599,7 @@ nsBrowserContentHandler.prototype = {
       if (urlFlagIdx > -1 && cmdLine.length > 1) {
         url = cmdLine.getArgument(urlFlagIdx + 1);
       }
-      if (privateWindowParam || url?.startsWith("firefox-private:")) {
+      if (privateWindowParam || url?.startsWith("firefox-private-bridge:")) {
         // Check if the osint flag is present on Windows
         let launchedWithArg_osint =
           AppConstants.platform == "win" &&
@@ -614,7 +614,7 @@ nsBrowserContentHandler.prototype = {
             uri: Services.io.newURI("about:privatebrowsing"),
             principal: lazy.gSystemPrincipal,
           };
-        } else if (url?.startsWith("firefox-private:")) {
+        } else if (url?.startsWith("firefox-private-bridge:")) {
           cmdLine.removeArguments(urlFlagIdx, urlFlagIdx + 1);
           resolvedInfo = resolveURIInternal(
             cmdLine,
@@ -1463,7 +1463,7 @@ nsDefaultCommandLineHandler.prototype = {
       }
 
       // Can't open multiple URLs without using system principal.
-      // The firefox and firefox-private protocols should only
+      // The firefox-bridge and firefox-private-bridge protocols should only
       // accept a single URL due to using the -osint option
       // so this isn't very relevant.
       var URLlist = urilist.filter(shouldLoadURI).map(u => u.spec);

browser/components/BrowserGlue.sys.mjs

@@ -38,6 +38,8 @@ ChromeUtils.defineESModuleGetters(lazy, {
   E10SUtils: "resource://gre/modules/E10SUtils.sys.mjs",
   ExtensionsUI: "resource:///modules/ExtensionsUI.sys.mjs",
   FeatureGate: "resource://featuregates/FeatureGate.sys.mjs",
+  FirefoxBridgeExtensionUtils:
+    "resource:///modules/FirefoxBridgeExtensionUtils.sys.mjs",
   FxAccounts: "resource://gre/modules/FxAccounts.sys.mjs",
   HomePage: "resource:///modules/HomePage.sys.mjs",
   Integration: "resource://gre/modules/Integration.sys.mjs",
@@ -2641,126 +2643,6 @@ BrowserGlue.prototype = {
         },
       },
 
-      {
-        name: "dualBrowserProtocolHandler",
-        condition:
-          AppConstants.platform == "win" &&
-          !Services.prefs.getBoolPref(
-            "browser.shell.customProtocolsRegistered"
-          ),
-        task: async () => {
-          Services.prefs.setBoolPref(
-            "browser.shell.customProtocolsRegistered",
-            true
-          );
-          const FIREFOX_HANDLER_NAME = "firefox";
-          const FIREFOX_PRIVATE_HANDLER_NAME = "firefox-private";
-          const path = Services.dirsvc.get("XREExeF", Ci.nsIFile).path;
-          let wrk = Cc["@mozilla.org/windows-registry-key;1"].createInstance(
-            Ci.nsIWindowsRegKey
-          );
-          try {
-            wrk.open(wrk.ROOT_KEY_CLASSES_ROOT, "", wrk.ACCESS_READ);
-            let FxSet = wrk.hasChild(FIREFOX_HANDLER_NAME);
-            let FxPrivateSet = wrk.hasChild(FIREFOX_PRIVATE_HANDLER_NAME);
-            wrk.close();
-            if (FxSet && FxPrivateSet) {
-              return;
-            }
-            wrk.open(
-              wrk.ROOT_KEY_CURRENT_USER,
-              "Software\\Classes",
-              wrk.ACCESS_ALL
-            );
-            const maybeUpdateRegistry = (
-              isSetAlready,
-              handler,
-              protocolName
-            ) => {
-              if (isSetAlready) {
-                return;
-              }
-              let FxKey = wrk.createChild(handler, wrk.ACCESS_ALL);
-              try {
-                // Write URL protocol key
-                FxKey.writeStringValue("", protocolName);
-                FxKey.writeStringValue("URL Protocol", "");
-                FxKey.close();
-                // Write defaultIcon key
-                FxKey.create(
-                  FxKey.ROOT_KEY_CURRENT_USER,
-                  "Software\\Classes\\" + handler + "\\DefaultIcon",
-                  FxKey.ACCESS_ALL
-                );
-                FxKey.open(
-                  FxKey.ROOT_KEY_CURRENT_USER,
-                  "Software\\Classes\\" + handler + "\\DefaultIcon",
-                  FxKey.ACCESS_ALL
-                );
-                FxKey.writeStringValue("", `\"${path}\",1`);
-                FxKey.close();
-                // Write shell\\open\\command key
-                FxKey.create(
-                  FxKey.ROOT_KEY_CURRENT_USER,
-                  "Software\\Classes\\" + handler + "\\shell",
-                  FxKey.ACCESS_ALL
-                );
-                FxKey.create(
-                  FxKey.ROOT_KEY_CURRENT_USER,
-                  "Software\\Classes\\" + handler + "\\shell\\open",
-                  FxKey.ACCESS_ALL
-                );
-                FxKey.create(
-                  FxKey.ROOT_KEY_CURRENT_USER,
-                  "Software\\Classes\\" + handler + "\\shell\\open\\command",
-                  FxKey.ACCESS_ALL
-                );
-                FxKey.open(
-                  FxKey.ROOT_KEY_CURRENT_USER,
-                  "Software\\Classes\\" + handler + "\\shell\\open\\command",
-                  FxKey.ACCESS_ALL
-                );
-                if (handler == FIREFOX_PRIVATE_HANDLER_NAME) {
-                  FxKey.writeStringValue(
-                    "",
-                    `\"${path}\" -osint -private-window \"%1\"`
-                  );
-                } else {
-                  FxKey.writeStringValue("", `\"${path}\" -osint -url \"%1\"`);
-                }
-              } catch (ex) {
-                console.log(ex);
-              } finally {
-                FxKey.close();
-              }
-            };
-            try {
-              maybeUpdateRegistry(
-                FxSet,
-                FIREFOX_HANDLER_NAME,
-                "URL:Firefox Protocol"
-              );
-            } catch (ex) {
-              console.log(ex);
-            }
-            try {
-              maybeUpdateRegistry(
-                FxPrivateSet,
-                FIREFOX_PRIVATE_HANDLER_NAME,
-                "URL:Firefox Private Browsing Protocol"
-              );
-            } catch (ex) {
-              console.log(ex);
-            }
-          } catch (ex) {
-            console.log(ex);
-          } finally {
-            wrk.close();
-          }
-        },
-        timeout: 5000,
-      },
-
       // Ensure a Private Browsing Shortcut exists. This is needed in case
       // a user tries to use Windows functionality to pin our Private Browsing
       // mode icon to the Taskbar (eg: the "Pin to Taskbar" context menu item).
@@ -3821,13 +3703,20 @@ BrowserGlue.prototype = {
   _migrateUI() {
     // Use an increasing number to keep track of the current migration state.
     // Completely unrelated to the current Firefox release number.
-    const UI_VERSION = 142;
+    const UI_VERSION = 143;
     const BROWSER_DOCURL = AppConstants.BROWSER_CHROME_URL;
 
     if (!Services.prefs.prefHasUserValue("browser.migration.version")) {
       // This is a new profile, nothing to migrate.
       Services.prefs.setIntPref("browser.migration.version", UI_VERSION);
       this._isNewProfile = true;
+
+      if (AppConstants.platform == "win") {
+        // Ensure that the Firefox Bridge protocols are registered for the new profile.
+        // No-op if they are registered for the user or the local machine already.
+        lazy.FirefoxBridgeExtensionUtils.maybeRegisterFirefoxBridgeProtocols();
+      }
+
       return;
     }
 
@@ -4427,6 +4316,27 @@ BrowserGlue.prototype = {
       }
     }
 
+    if (currentUIVersion < 143) {
+      if (AppConstants.platform == "win") {
+        // In Firefox 122, we enabled the firefox and firefox-private protocols.
+        // We switched over to using firefox-bridge and firefox-private-bridge,
+        // but we want to clean up the use of the other protocols.
+        lazy.FirefoxBridgeExtensionUtils.maybeDeleteBridgeProtocolRegistryEntries();
+
+        // Register the new firefox bridge related protocols now
+        lazy.FirefoxBridgeExtensionUtils.maybeRegisterFirefoxBridgeProtocols();
+
+        // Clean up the old user prefs from FX 122
+        Services.prefs.clearUserPref(
+          "network.protocol-handler.external.firefox"
+        );
+        Services.prefs.clearUserPref(
+          "network.protocol-handler.external.firefox-private"
+        );
+        Services.prefs.clearUserPref("browser.shell.customProtocolsRegistered");
+      }
+    }
+
     // Update the migration version.
     Services.prefs.setIntPref("browser.migration.version", UI_VERSION);
   },

browser/installer/windows/msix/AppxManifest.xml.in

@@ -92,14 +92,14 @@
           </uap3:Protocol>
         </uap3:Extension>
         <uap3:Extension Category="windows.protocol">
-          <uap3:Protocol Name="firefox" Parameters="-osint -url &quot;%1&quot;">
+          <uap3:Protocol Name="firefox-bridge" Parameters="-osint -url &quot;%1&quot;">
-            <uap:DisplayName>Firefox Protocol</uap:DisplayName>
+            <uap:DisplayName>Firefox Bridge Protocol</uap:DisplayName>
             <uap:Logo>Assets\Document44x44.png</uap:Logo>
           </uap3:Protocol>
         </uap3:Extension>
         <uap3:Extension Category="windows.protocol">
-          <uap3:Protocol Name="firefox-private" Parameters="-osint -private-window &quot;%1&quot;">
+          <uap3:Protocol Name="firefox-private-bridge" Parameters="-osint -private-window &quot;%1&quot;">
-            <uap:DisplayName>Firefox Private Browsing Protocol</uap:DisplayName>
+            <uap:DisplayName>Firefox Private Bridge Protocol</uap:DisplayName>
             <uap:Logo>Assets\Document44x44.png</uap:Logo>
           </uap3:Protocol>
         </uap3:Extension>

browser/installer/windows/nsis/installer.nsi

@@ -474,22 +474,22 @@ Section "-Application" APP_IDX
   ${AddDisabledDDEHandlerValues} "FirefoxURL-$AppUserModelID" "$2" "$8,${IDI_DOCUMENT_ZERO_BASED}" \
                                  "${AppRegName} URL" "true"
 
-  ; Create protocol registry keys for dual browser extensions - only if not already set
+  ; Create protocol registry keys for FirefoxBridge extensions - only if not already set
   SetShellVarContext current  ; Set SHCTX to HKCU
-  !define FIREFOX_PROTOCOL "firefox"
+  !define FIREFOX_PROTOCOL "firefox-bridge"
   ClearErrors
   ReadRegStr $0 SHCTX "Software\Classes\${FIREFOX_PROTOCOL}" ""
   ${If} $0 == ""
     ${AddDisabledDDEHandlerValues} "${FIREFOX_PROTOCOL}" "$2" "$8,${IDI_APPICON_ZERO_BASED}" \
-                                   "Firefox Browsing Protocol" "true"
+                                   "Firefox Bridge Protocol" "true"
   ${EndIf}
 
-  !define FIREFOX_PRIVATE_PROTOCOL "firefox-private"
+  !define FIREFOX_PRIVATE_PROTOCOL "firefox-private-bridge"
   ClearErrors
   ReadRegStr $0 SHCTX "Software\Classes\${FIREFOX_PRIVATE_PROTOCOL}" ""
   ${If} $0 == ""
     ${AddDisabledDDEHandlerValues} "${FIREFOX_PRIVATE_PROTOCOL}" "$\"$8$\" -osint -private-window $\"%1$\"" \
-                                   "$8,${IDI_PBICON_PB_EXE_ZERO_BASED}" "Firefox Private Browsing Protocol" "true"
+                                   "$8,${IDI_PBICON_PB_EXE_ZERO_BASED}" "Firefox Private Bridge Protocol" "true"
   ${EndIf}
   SetShellVarContext all  ; Set SHCTX to HKLM
 
@@ -794,6 +794,15 @@ Section "-InstallEndCleanup"
   ; Refresh desktop icons
   ${RefreshShellIcons}
 
+  ; Remove old unsupported firefox and firefox-private extension protocol
+  ; handlers which were added in FX122 for the dual browser extension, since
+  ; renamed to FirefoxBridge
+  Push $1
+  ${GetLongPath} "$INSTDIR\${FileMainEXE}" $1
+  ${DeleteProtocolRegistryIfSetToInstallation} "$1" "firefox"
+  ${DeleteProtocolRegistryIfSetToInstallation} "$1" "firefox-private"
+  Pop $1
+
   ${InstallEndCleanupCommon}
 
   ${If} $PreventRebootRequired == "true"

browser/installer/windows/nsis/shared.nsh

@@ -1824,3 +1824,49 @@ FunctionEnd
   ${WriteRegStr2} ${RegKey} "Software\Classes\CLSID\$0\InProcServer32" "" "$INSTDIR\notificationserver.dll" 0
 !macroend
 !define WriteToastNotificationRegistration "!insertmacro WriteToastNotificationRegistration"
+
+/**
+ * Deletes the registry keys for a protocol handler but only if those registry
+ * keys were pointed to the installation being uninstalled.
+ * Does this with both the HKLM and the HKCU registry entries.
+ *
+ * @param   _PROTOCOL
+ *          The protocol to delete the registry keys for
+ */
+!macro DeleteProtocolRegistryIfSetToInstallation INSTALL_PATH _PROTOCOL
+  Push $0
+
+  ; Check if there is a protocol handler registered by fetching the DefaultIcon value
+  ; in the registry.
+  ; If there is something registered for the icon, it will be the path to the executable,
+  ; plus a comma and a number for the id of the resource for the icon.
+  ; Use StrCpy with -2 to remove the comma and the resource id so that
+  ; the whole path to the executable can be compared against what's being
+  ; uninstalled.
+
+  ; Do all of that twice, once for the local machine and once for the current user
+  
+  ; Remove protocol handlers
+  ClearErrors
+  ReadRegStr $0 HKLM "Software\Classes\${_PROTOCOL}\DefaultIcon" ""
+  ${If} $0 != ""
+    StrCpy $0 $0 -2
+    ${If} $0 == '"${INSTALL_PATH}"'
+      DeleteRegKey HKLM "Software\Classes\${_PROTOCOL}"
+    ${EndIf}
+  ${EndIf}
+
+  ClearErrors
+  ReadRegStr $0 HKCU "Software\Classes\${_PROTOCOL}\DefaultIcon" ""
+  ${If} $0 != ""
+    StrCpy $0 $0 -2
+    ${If} $0 == '"${INSTALL_PATH}"'
+      DeleteRegKey HKCU "Software\Classes\${_PROTOCOL}"
+    ${EndIf}
+  ${EndIf}
+
+  ClearErrors
+
+  Pop $0
+!macroend
+!define DeleteProtocolRegistryIfSetToInstallation '!insertmacro DeleteProtocolRegistryIfSetToInstallation'

browser/installer/windows/nsis/uninstaller.nsi

@@ -411,54 +411,6 @@ SectionEnd
 ################################################################################
 # Uninstall Sections
 
-/**
- * Deletes the registry keys for a protocol handler but only if those registry
- * keys were pointed to the installation being uninstalled.
- * Does this with both the HKLM and the HKCU registry entries.
- *
- * @param   _PROTOCOL
- *          The protocol to delete the registry keys for
- */
-!macro DeleteProtocolRegistryIfSetToInstallation _PROTOCOL
-  Push $0
-  Push $1
-  ; Check if there is a protocol handler registered by fetching the DefaultIcon value
-  ; in the registry.
-  ; If there is something registered for the icon, it will be the path to the executable,
-  ; plus a comma and a number for the id of the resource for the icon.
-  ; Use StrCpy with -2 to remove the comma and the resource id so that
-  ; the whole path to the executable can be compared against what's being
-  ; uninstalled.
-
-  ; Do all of that twice, once for the local machine and once for the current user
-
-  ; Remove protocol handlers
-  ClearErrors
-  ${un.GetLongPath} "$INSTDIR\${FileMainEXE}" $1
-  ReadRegStr $0 HKLM "Software\Classes\${_PROTOCOL}\DefaultIcon" ""
-  ${If} $0 != ""
-    StrCpy $0 $0 -2
-    ${If} $0 == $1
-      DeleteRegKey HKLM "Software\Classes\${_PROTOCOL}"
-    ${EndIf}
-  ${EndIf}
-
-  ClearErrors
-  ReadRegStr $0 HKCU "Software\Classes\${_PROTOCOL}\DefaultIcon" ""
-  ${If} $0 != ""
-    StrCpy $0 $0 -2
-    ${If} $0 == $1
-      DeleteRegKey HKCU "Software\Classes\${_PROTOCOL}"
-    ${EndIf}
-  ${EndIf}
-
-  ClearErrors
-
-  Pop $0
-  Pop $1
-!macroend
-!define DeleteProtocolRegistryIfSetToInstallation '!insertmacro DeleteProtocolRegistryIfSetToInstallation'
-
 Section "Uninstall"
   SetDetailsPrint textonly
   DetailPrint $(STATUS_UNINSTALL_MAIN)
@@ -571,9 +523,12 @@ Section "Uninstall"
   ; Clean up "launch on login" registry key for this installation.
   DeleteRegValue HKCU "Software\Microsoft\Windows\CurrentVersion\Run" "Mozilla-${AppName}-$AppUserModelID"
 
-  ; Remove dual browser extension protocol handlers
+  ; Remove FirefoxBridge extension protocol handlers
-  ${DeleteProtocolRegistryIfSetToInstallation} "firefox"
+  Push $1
-  ${DeleteProtocolRegistryIfSetToInstallation} "firefox-private"
+  ${un.GetLongPath} "$INSTDIR\${FileMainEXE}" $1
+  ${DeleteProtocolRegistryIfSetToInstallation} "$1" "firefox-bridge"
+  ${DeleteProtocolRegistryIfSetToInstallation} "$1" "firefox-private-bridge"
+  Pop $1
 
   ; Remove old protocol handler and StartMenuInternet keys without install path
   ; hashes, but only if they're for this installation.  We've never supported

browser/modules/FirefoxBridgeExtensionUtils.sys.mjs

@@ -0,0 +1,222 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Default implementation of the helper class to assist in deleting the firefox protocols.
+ * See maybeDeleteBridgeProtocolRegistryEntries for more info.
+ */
+class DeleteBridgeProtocolRegistryEntryHelperImplementation {
+  getApplicationPath() {
+    return Services.dirsvc.get("XREExeF", Ci.nsIFile).path;
+  }
+
+  openRegistryRoot() {
+    const wrk = Cc["@mozilla.org/windows-registry-key;1"].createInstance(
+      Ci.nsIWindowsRegKey
+    );
+
+    wrk.open(wrk.ROOT_KEY_CURRENT_USER, "Software\\Classes", wrk.ACCESS_ALL);
+
+    return wrk;
+  }
+
+  deleteChildren(start) {
+    // Recursively delete all of the children of the children
+    // Go through the list in reverse order, so that shrinking
+    // the list doesn't rearrange things while iterating
+    for (let i = start.childCount; i > 0; i--) {
+      const childName = start.getChildName(i - 1);
+      const child = start.openChild(childName, start.ACCESS_ALL);
+      this.deleteChildren(child);
+      child.close();
+
+      start.removeChild(childName);
+    }
+  }
+
+  deleteRegistryTree(root, toDeletePath) {
+    var start = root.openChild(toDeletePath, root.ACCESS_ALL);
+    this.deleteChildren(start);
+    start.close();
+
+    root.removeChild(toDeletePath);
+  }
+}
+
+export const FirefoxBridgeExtensionUtils = {
+  /**
+   * In Firefox 122, we enabled the firefox and firefox-private protocols.
+   * We switched over to using firefox-bridge and firefox-private-bridge,
+   *
+   * but we want to clean up the use of the other protocols.
+   *
+   * deleteBridgeProtocolRegistryEntryHelper handles everything outside of the logic needed for
+   * this method so that the logic in maybeDeleteBridgeProtocolRegistryEntries can be unit tested
+   *
+   * We only delete the entries for the firefox and firefox-private protocols if
+   * they were set up to use this install and in the format that Firefox installed
+   * them with. If the entries are changed in any way, it is assumed that the user
+   * mucked with them manually and knows what they are doing.
+   */
+  maybeDeleteBridgeProtocolRegistryEntries(
+    deleteBridgeProtocolRegistryEntryHelper = new DeleteBridgeProtocolRegistryEntryHelperImplementation()
+  ) {
+    try {
+      var wrk = deleteBridgeProtocolRegistryEntryHelper.openRegistryRoot();
+      const path = deleteBridgeProtocolRegistryEntryHelper.getApplicationPath();
+
+      const maybeDeleteRegistryKey = (protocol, protocolCommand) => {
+        const openCommandPath = protocol + "\\shell\\open\\command";
+        if (wrk.hasChild(openCommandPath)) {
+          let deleteProtocolEntry = false;
+
+          try {
+            var openCommandKey = wrk.openChild(
+              openCommandPath,
+              wrk.ACCESS_READ
+            );
+            if (openCommandKey.valueCount == 1) {
+              const defaultKeyName = "";
+              if (openCommandKey.getValueName(0) == defaultKeyName) {
+                if (
+                  openCommandKey.getValueType(defaultKeyName) ==
+                  Ci.nsIWindowsRegKey.TYPE_STRING
+                ) {
+                  const val = openCommandKey.readStringValue(defaultKeyName);
+                  if (val == protocolCommand) {
+                    deleteProtocolEntry = true;
+                  }
+                }
+              }
+            }
+          } finally {
+            openCommandKey.close();
+          }
+
+          if (deleteProtocolEntry) {
+            deleteBridgeProtocolRegistryEntryHelper.deleteRegistryTree(
+              wrk,
+              protocol
+            );
+          }
+        }
+      };
+
+      maybeDeleteRegistryKey("firefox", `\"${path}\" -osint -url \"%1\"`);
+      maybeDeleteRegistryKey(
+        "firefox-private",
+        `\"${path}\" -osint -private-window \"%1\"`
+      );
+    } catch (err) {
+      console.error(err);
+    } finally {
+      wrk.close();
+    }
+  },
+
+  /**
+   * Registers the firefox-bridge and firefox-private-bridge protocols
+   * on the Windows platform.
+   */
+  maybeRegisterFirefoxBridgeProtocols() {
+    const FIREFOX_BRIDGE_HANDLER_NAME = "firefox-bridge";
+    const FIREFOX_PRIVATE_BRIDGE_HANDLER_NAME = "firefox-private-bridge";
+    const path = Services.dirsvc.get("XREExeF", Ci.nsIFile).path;
+    let wrk = Cc["@mozilla.org/windows-registry-key;1"].createInstance(
+      Ci.nsIWindowsRegKey
+    );
+    try {
+      wrk.open(wrk.ROOT_KEY_CLASSES_ROOT, "", wrk.ACCESS_READ);
+      let FxSet = wrk.hasChild(FIREFOX_BRIDGE_HANDLER_NAME);
+      let FxPrivateSet = wrk.hasChild(FIREFOX_PRIVATE_BRIDGE_HANDLER_NAME);
+      wrk.close();
+      if (FxSet && FxPrivateSet) {
+        return;
+      }
+      wrk.open(wrk.ROOT_KEY_CURRENT_USER, "Software\\Classes", wrk.ACCESS_ALL);
+      const maybeUpdateRegistry = (isSetAlready, handler, protocolName) => {
+        if (isSetAlready) {
+          return;
+        }
+        let FxKey = wrk.createChild(handler, wrk.ACCESS_ALL);
+        try {
+          // Write URL protocol key
+          FxKey.writeStringValue("", protocolName);
+          FxKey.writeStringValue("URL Protocol", "");
+          FxKey.close();
+          // Write defaultIcon key
+          FxKey.create(
+            FxKey.ROOT_KEY_CURRENT_USER,
+            "Software\\Classes\\" + handler + "\\DefaultIcon",
+            FxKey.ACCESS_ALL
+          );
+          FxKey.open(
+            FxKey.ROOT_KEY_CURRENT_USER,
+            "Software\\Classes\\" + handler + "\\DefaultIcon",
+            FxKey.ACCESS_ALL
+          );
+          FxKey.writeStringValue("", `\"${path}\",1`);
+          FxKey.close();
+          // Write shell\\open\\command key
+          FxKey.create(
+            FxKey.ROOT_KEY_CURRENT_USER,
+            "Software\\Classes\\" + handler + "\\shell",
+            FxKey.ACCESS_ALL
+          );
+          FxKey.create(
+            FxKey.ROOT_KEY_CURRENT_USER,
+            "Software\\Classes\\" + handler + "\\shell\\open",
+            FxKey.ACCESS_ALL
+          );
+          FxKey.create(
+            FxKey.ROOT_KEY_CURRENT_USER,
+            "Software\\Classes\\" + handler + "\\shell\\open\\command",
+            FxKey.ACCESS_ALL
+          );
+          FxKey.open(
+            FxKey.ROOT_KEY_CURRENT_USER,
+            "Software\\Classes\\" + handler + "\\shell\\open\\command",
+            FxKey.ACCESS_ALL
+          );
+          if (handler == FIREFOX_PRIVATE_BRIDGE_HANDLER_NAME) {
+            FxKey.writeStringValue(
+              "",
+              `\"${path}\" -osint -private-window \"%1\"`
+            );
+          } else {
+            FxKey.writeStringValue("", `\"${path}\" -osint -url \"%1\"`);
+          }
+        } catch (ex) {
+          console.error(ex);
+        } finally {
+          FxKey.close();
+        }
+      };
+
+      try {
+        maybeUpdateRegistry(
+          FxSet,
+          FIREFOX_BRIDGE_HANDLER_NAME,
+          "URL:Firefox Bridge Protocol"
+        );
+      } catch (ex) {
+        console.error(ex);
+      }
+
+      try {
+        maybeUpdateRegistry(
+          FxPrivateSet,
+          FIREFOX_PRIVATE_BRIDGE_HANDLER_NAME,
+          "URL:Firefox Private Bridge Protocol"
+        );
+      } catch (ex) {
+        console.error(ex);
+      }
+    } catch (ex) {
+      console.error(ex);
+    } finally {
+      wrk.close();
+    }
+  },
+};

browser/modules/moz.build

@@ -7,6 +7,12 @@
 with Files("**"):
     BUG_COMPONENT = ("Firefox", "General")
 
+with Files("FirefoxBridgeExtensionUtils.sys.mjs"):
+    BUG_COMPONENT = ("Firefox", "Shell Integration")
+
+with Files("test/unit/test_FirefoxBridgeExtensionUtils.sys.mjs"):
+    BUG_COMPONENT = ("Firefox", "Shell Integration")
+
 with Files("test/browser/*Telemetry*"):
     BUG_COMPONENT = ("Toolkit", "Telemetry")
 
@@ -128,6 +134,7 @@ EXTRA_JS_MODULES += [
     "EveryWindow.sys.mjs",
     "ExtensionsUI.sys.mjs",
     "FaviconLoader.sys.mjs",
+    "FirefoxBridgeExtensionUtils.sys.mjs",
     "HomePage.sys.mjs",
     "LaterRun.sys.mjs",
     "NewTabPagePreloading.sys.mjs",

browser/modules/test/unit/test_FirefoxBridgeExtensionUtils.js

@@ -0,0 +1,350 @@
+/* Any copyright is dedicated to the Public Domain.
+http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { FirefoxBridgeExtensionUtils } = ChromeUtils.importESModule(
+  "resource:///modules/FirefoxBridgeExtensionUtils.sys.mjs"
+);
+
+const FIREFOX_SHELL_OPEN_COMMAND_PATH = "firefox\\shell\\open\\command";
+const FIREFOX_PRIVATE_SHELL_OPEN_COMMAND_PATH =
+  "firefox-private\\shell\\open\\command";
+
+class StubbedRegistryKey {
+  #children;
+  #originalChildren;
+  #closeCalled;
+  #deletedChildren;
+  #openedForRead;
+  #values;
+
+  constructor(children, values) {
+    this.#children = children;
+    this.#values = values;
+    this.#originalChildren = new Map(children);
+
+    this.#closeCalled = false;
+    this.#openedForRead = false;
+    this.#deletedChildren = new Set([]);
+  }
+
+  get ACCESS_READ() {
+    return 0;
+  }
+
+  reset() {
+    this.#closeCalled = false;
+    this.#deletedChildren = new Set([]);
+    this.#children = new Map(this.#originalChildren);
+  }
+
+  open(accessLevel) {
+    this.#openedForRead = true;
+  }
+
+  get wasOpenedForRead() {
+    return this.#openedForRead;
+  }
+
+  openChild(path, accessLevel) {
+    const result = this.#children.get(path);
+    result?.open(accessLevel);
+    return result;
+  }
+
+  hasChild(path) {
+    return this.#children.has(path);
+  }
+
+  close() {
+    this.#closeCalled = true;
+  }
+
+  removeChild(path) {
+    this.#deletedChildren.add(path);
+
+    // delete the actual child if it's in there
+    this.#children.delete(path);
+  }
+
+  isChildDeleted(path) {
+    return this.#deletedChildren.has(path);
+  }
+
+  getChildName(index) {
+    let i = 0;
+    for (const [key] of this.#children) {
+      if (i == index) {
+        return key;
+      }
+      i++;
+    }
+
+    return undefined;
+  }
+
+  readStringValue(name) {
+    return this.#values.get(name);
+  }
+
+  get childCount() {
+    return this.#children.size;
+  }
+
+  getValueType(entryName) {
+    if (typeof this.readStringValue(entryName) == "string") {
+      return Ci.nsIWindowsRegKey.TYPE_STRING;
+    }
+
+    throw new Error(`${entryName} not found in registry`);
+  }
+
+  get wasCloseCalled() {
+    return this.#closeCalled;
+  }
+
+  getValueName(index) {
+    let i = 0;
+    for (const [key] of this.#values) {
+      if (i == index) {
+        return key;
+      }
+      i++;
+    }
+
+    return undefined;
+  }
+
+  get valueCount() {
+    return this.#values.size;
+  }
+}
+
+class StubbedDeleteBridgeProtocolRegistryEntryHelper {
+  #applicationPath;
+  #registryRootKey;
+
+  constructor({ applicationPath, registryRootKey }) {
+    this.#applicationPath = applicationPath;
+    this.#registryRootKey = registryRootKey;
+  }
+
+  getApplicationPath() {
+    return this.#applicationPath;
+  }
+
+  openRegistryRoot() {
+    return this.#registryRootKey;
+  }
+
+  deleteRegistryTree(root, toDeletePath) {
+    // simplify this for tests
+    root.removeChild(toDeletePath);
+  }
+}
+
+add_task(async function test_DeleteWhenSameFirefoxInstall() {
+  const applicationPath = "testPath";
+
+  const firefoxEntries = new Map();
+  firefoxEntries.set("", `\"${applicationPath}\" -osint -url \"%1\"`);
+
+  const firefoxProtocolRegKey = new StubbedRegistryKey(
+    new Map(),
+    firefoxEntries
+  );
+
+  const firefoxPrivateEntries = new Map();
+  firefoxPrivateEntries.set(
+    "",
+    `\"${applicationPath}\" -osint -private-window \"%1\"`
+  );
+  const firefoxPrivateProtocolRegKey = new StubbedRegistryKey(
+    new Map(),
+    firefoxPrivateEntries
+  );
+
+  const children = new Map();
+  children.set(FIREFOX_SHELL_OPEN_COMMAND_PATH, firefoxProtocolRegKey);
+  children.set(
+    FIREFOX_PRIVATE_SHELL_OPEN_COMMAND_PATH,
+    firefoxPrivateProtocolRegKey
+  );
+
+  const registryRootKey = new StubbedRegistryKey(children, new Map());
+
+  const stubbedDeleteBridgeProtocolRegistryHelper =
+    new StubbedDeleteBridgeProtocolRegistryEntryHelper({
+      applicationPath,
+      registryRootKey,
+    });
+
+  FirefoxBridgeExtensionUtils.maybeDeleteBridgeProtocolRegistryEntries(
+    stubbedDeleteBridgeProtocolRegistryHelper
+  );
+
+  ok(registryRootKey.wasCloseCalled, "Root key closed");
+
+  ok(firefoxProtocolRegKey.wasOpenedForRead, "Firefox key opened");
+  ok(firefoxProtocolRegKey.wasCloseCalled, "Firefox key closed");
+  ok(
+    registryRootKey.isChildDeleted("firefox"),
+    "Firefox protocol registry entry deleted"
+  );
+
+  ok(
+    firefoxPrivateProtocolRegKey.wasOpenedForRead,
+    "Firefox private key opened"
+  );
+  ok(firefoxPrivateProtocolRegKey.wasCloseCalled, "Firefox private key closed");
+  ok(
+    registryRootKey.isChildDeleted("firefox-private"),
+    "Firefox private protocol registry entry deleted"
+  );
+});
+
+add_task(async function test_DeleteWhenDifferentFirefoxInstall() {
+  const applicationPath = "testPath";
+  const badApplicationPath = "testPath2";
+
+  const firefoxEntries = new Map();
+  firefoxEntries.set("", `\"${badApplicationPath}\" -osint -url \"%1\"`);
+
+  const firefoxProtocolRegKey = new StubbedRegistryKey(
+    new Map(),
+    firefoxEntries
+  );
+
+  const firefoxPrivateEntries = new Map();
+  firefoxPrivateEntries.set(
+    "",
+    `\"${badApplicationPath}\" -osint -private-window \"%1\"`
+  );
+  const firefoxPrivateProtocolRegKey = new StubbedRegistryKey(
+    new Map(),
+    firefoxPrivateEntries
+  );
+
+  const children = new Map();
+  children.set(FIREFOX_SHELL_OPEN_COMMAND_PATH, firefoxProtocolRegKey);
+  children.set(
+    FIREFOX_PRIVATE_SHELL_OPEN_COMMAND_PATH,
+    firefoxPrivateProtocolRegKey
+  );
+
+  const registryRootKey = new StubbedRegistryKey(children, new Map());
+
+  const stubbedDeleteBridgeProtocolRegistryHelper =
+    new StubbedDeleteBridgeProtocolRegistryEntryHelper({
+      applicationPath,
+      registryRootKey,
+    });
+
+  FirefoxBridgeExtensionUtils.maybeDeleteBridgeProtocolRegistryEntries(
+    stubbedDeleteBridgeProtocolRegistryHelper
+  );
+
+  ok(registryRootKey.wasCloseCalled, "Root key closed");
+
+  ok(firefoxProtocolRegKey.wasOpenedForRead, "Firefox key opened");
+  ok(firefoxProtocolRegKey.wasCloseCalled, "Firefox key closed");
+  ok(
+    !registryRootKey.isChildDeleted("firefox"),
+    "Firefox protocol registry entry not deleted"
+  );
+
+  ok(
+    firefoxPrivateProtocolRegKey.wasOpenedForRead,
+    "Firefox private key opened"
+  );
+  ok(firefoxPrivateProtocolRegKey.wasCloseCalled, "Firefox private key closed");
+  ok(
+    !registryRootKey.isChildDeleted("firefox-private"),
+    "Firefox private protocol registry entry not deleted"
+  );
+});
+
+add_task(async function test_DeleteWhenNoRegistryEntries() {
+  const applicationPath = "testPath";
+
+  const firefoxPrivateEntries = new Map();
+  const firefoxPrivateProtocolRegKey = new StubbedRegistryKey(
+    new Map(),
+    firefoxPrivateEntries
+  );
+
+  const children = new Map();
+  children.set(
+    FIREFOX_PRIVATE_SHELL_OPEN_COMMAND_PATH,
+    firefoxPrivateProtocolRegKey
+  );
+
+  const registryRootKey = new StubbedRegistryKey(children, new Map());
+
+  const stubbedDeleteBridgeProtocolRegistryHelper =
+    new StubbedDeleteBridgeProtocolRegistryEntryHelper({
+      applicationPath,
+      registryRootKey,
+    });
+
+  FirefoxBridgeExtensionUtils.maybeDeleteBridgeProtocolRegistryEntries(
+    stubbedDeleteBridgeProtocolRegistryHelper
+  );
+
+  ok(registryRootKey.wasCloseCalled, "Root key closed");
+
+  ok(
+    firefoxPrivateProtocolRegKey.wasOpenedForRead,
+    "Firefox private key opened"
+  );
+  ok(firefoxPrivateProtocolRegKey.wasCloseCalled, "Firefox private key closed");
+  ok(
+    !registryRootKey.isChildDeleted("firefox"),
+    "Firefox protocol registry entry deleted when it shouldn't be"
+  );
+  ok(
+    !registryRootKey.isChildDeleted("firefox-private"),
+    "Firefox private protocol registry deleted when it shouldn't be"
+  );
+});
+
+add_task(async function test_DeleteWhenUnexpectedRegistryEntries() {
+  const applicationPath = "testPath";
+
+  const firefoxEntries = new Map();
+  firefoxEntries.set("", `\"${applicationPath}\" -osint -url \"%1\"`);
+  firefoxEntries.set("extraEntry", "extraValue");
+  const firefoxProtocolRegKey = new StubbedRegistryKey(
+    new Map(),
+    firefoxEntries
+  );
+
+  const children = new Map();
+  children.set(FIREFOX_SHELL_OPEN_COMMAND_PATH, firefoxProtocolRegKey);
+
+  const registryRootKey = new StubbedRegistryKey(children, new Map());
+
+  const stubbedDeleteBridgeProtocolRegistryHelper =
+    new StubbedDeleteBridgeProtocolRegistryEntryHelper({
+      applicationPath,
+      registryRootKey,
+    });
+
+  FirefoxBridgeExtensionUtils.maybeDeleteBridgeProtocolRegistryEntries(
+    stubbedDeleteBridgeProtocolRegistryHelper
+  );
+
+  ok(registryRootKey.wasCloseCalled, "Root key closed");
+
+  ok(firefoxProtocolRegKey.wasOpenedForRead, "Firefox key opened");
+  ok(firefoxProtocolRegKey.wasCloseCalled, "Firefox key closed");
+  ok(
+    !registryRootKey.isChildDeleted("firefox"),
+    "Firefox protocol registry entry deleted when it shouldn't be"
+  );
+  ok(
+    !registryRootKey.isChildDeleted("firefox-private"),
+    "Firefox private protocol registry deleted when it shouldn't be"
+  );
+});

browser/modules/test/unit/xpcshell.toml

@@ -5,6 +5,9 @@ skip-if = ["os == 'android'"] # bug 1730213
 
 ["test_E10SUtils_nested_URIs.js"]
 
+["test_FirefoxBridgeExtensionUtils.js"]
+run-if = ["os == 'win'"] # Test of a Windows-specific feature
+
 ["test_HomePage.js"]
 
 ["test_HomePage_ignore.js"]

modules/libpref/init/all.js

@@ -1074,8 +1074,8 @@ pref("network.protocol-handler.external.disk", false);
 pref("network.protocol-handler.external.disks", false);
 pref("network.protocol-handler.external.afp", false);
 pref("network.protocol-handler.external.moz-icon", false);
-pref("network.protocol-handler.external.firefox", false);
+pref("network.protocol-handler.external.firefox-bridge", false);
-pref("network.protocol-handler.external.firefox-private", false);
+pref("network.protocol-handler.external.firefox-private-bridge", false);
 
 // Don't allow  external protocol handlers for common typos
 pref("network.protocol-handler.external.ttp", false);  // http