Bug 1567229 - Attempt creating a taskbar pin a second time on Windows 10. r=agashlin

At least for now, this behavior is behind a hidden pref. The intent is to
experiment with the feature and determine that way whether enabling it
permanently is a good idea, and if so the pref gate will be removed in a
separate bug.

This patch depends on bug 1567247 and will fail to build without it.

Differential Revision: https://phabricator.services.mozilla.com/D41100

--HG--
extra : moz-landing-system : lando

browser/components/installerprefs/InstallerPrefs.jsm

@@ -30,7 +30,7 @@ const INSTALLER_PREFS_BRANCH = "installer.";
 // current use (e.g., currently active experiments).
 // Only add prefs to this list which are in INSTALLER_PREFS_BRANCH;
 // any others will be ignored.
-const INSTALLER_PREFS_LIST = [];
+const INSTALLER_PREFS_LIST = ["installer.taskbarpin.win10.enabled"];
 
 const { AppConstants } = ChromeUtils.import(
   "resource://gre/modules/AppConstants.jsm"

browser/installer/windows/nsis/installer.nsi

@@ -121,6 +121,11 @@ VIAddVersionKey "OriginalFilename" "setup.exe"
 !insertmacro WriteRegStr2
 !insertmacro WriteRegDWORD2
 
+; This needs to be inserted after InitHashAppModelId because it uses
+; $AppUserModelID and the compiler can't handle using variables lexically before
+; they've been declared.
+!insertmacro GetInstallerRegistryPref
+
 !include shared.nsh
 
 ; Helper macros for ui callbacks. Insert these after shared.nsh

browser/installer/windows/nsis/shared.nsh

@@ -1099,6 +1099,7 @@
     ${If} ${Errors}
       ClearErrors
       WriteIniStr "$0" "TASKBAR" "Migrated" "true"
+      WriteINIStr "$0" "TASKBAR" "Pinned" "true"
       ${If} ${AtLeastWin7}
         ; If we didn't run the stub installer, AddTaskbarSC will be empty.
         ; We determine whether to pin based on whether we're the default
@@ -1121,6 +1122,24 @@
           ${PinToTaskBar}
         ${EndIf}
       ${EndIf}
+    ${ElseIf} ${AtLeastWin10}
+      ${GetInstallerRegistryPref} "Software\Mozilla\${AppName}" \
+        "installer.taskbarpin.win10.enabled" $2
+      ${If} $2 == "true"
+        ; On Windows 10, we may have previously tried to make a taskbar pin
+        ; and failed because the API we tried to use was blocked by the OS.
+        ; We have an option that works in more cases now, so we're going to try
+        ; again, but also record that we've done so by writing "Pinned" into the
+        ; shortcuts log, so that we don't continue to do this repeatedly.
+        ClearErrors
+        ReadINIStr $1 "$0" "TASKBAR" "Pinned"
+        ${If} ${Errors}
+          WriteINIStr "$0" "TASKBAR" "Pinned" "true"
+          ${If} $AddTaskbarSC != "0"
+            ${PinToTaskBar}
+          ${EndIf}
+        ${EndIf}
+      ${EndIf}
     ${EndIf}
   ${EndIf}
 !macroend

browser/installer/windows/nsis/uninstaller.nsi

@@ -93,6 +93,11 @@ VIAddVersionKey "OriginalFilename" "helper.exe"
 !insertmacro WriteRegDWORD2
 !insertmacro WriteRegStr2
 
+; This needs to be inserted after InitHashAppModelId because it uses
+; $AppUserModelID and the compiler can't handle using variables lexically before
+; they've been declared.
+!insertmacro GetInstallerRegistryPref
+
 !insertmacro un.ChangeMUIHeaderImage
 !insertmacro un.CheckForFilesInUse
 !insertmacro un.CleanUpdateDirectories