Fix cases of core taps being unnecessarily installed

Library/Homebrew/cmd/install.rb

@@ -179,9 +179,7 @@ module Homebrew
       next unless name =~ HOMEBREW_TAP_FORMULA_REGEX
 
       tap = Tap.fetch(Regexp.last_match(1), Regexp.last_match(2))
-      next if (tap.core_tap? || tap == "homebrew/cask") && !EnvConfig.no_install_from_api?
-
-      tap.install unless tap.installed?
+      tap.ensure_installed!
     end
 
     if args.ignore_dependencies?

Library/Homebrew/cmd/update-report.rb

@@ -600,7 +600,7 @@ class Reporter
         next unless (HOMEBREW_PREFIX/"Caskroom"/new_name).exist?
 
         new_tap = Tap.fetch(new_tap_name)
-        new_tap.install unless new_tap.installed?
+        new_tap.ensure_installed!
         ohai "#{name} has been moved to Homebrew.", <<~EOS
           To uninstall the cask, run:
             brew uninstall --cask --force #{name}
@@ -650,7 +650,7 @@ class Reporter
           EOS
         end
       else
-        new_tap.install unless new_tap.installed?
+        new_tap.ensure_installed!
         # update tap for each Tab
         tabs.each { |tab| tab.tap = new_tap }
         tabs.each(&:write)

Library/Homebrew/dev-cmd/extract.rb

@@ -107,6 +107,7 @@ module Homebrew
     destination_tap = Tap.fetch(args.named.second)
     unless Homebrew::EnvConfig.developer?
       odie "Cannot extract formula to homebrew/core!" if destination_tap.core_tap?
+      odie "Cannot extract formula to homebrew/cask!" if destination_tap.core_cask_tap?
       odie "Cannot extract formula to the same tap!" if destination_tap == source_tap
     end
     destination_tap.install unless destination_tap.installed?

Library/Homebrew/formula_installer.rb

@@ -229,8 +229,8 @@ class FormulaInstaller
     rescue TapFormulaUnavailableError => e
       raise if e.tap.installed?
 
-      e.tap.install
-      retry
+      e.tap.ensure_installed!
+      retry if e.tap.installed? # It may have not installed if it's a core tap.
     end
   rescue FormulaUnavailableError => e
     e.dependent = formula.full_name

Library/Homebrew/formulary.rb

@@ -626,7 +626,7 @@ module Formulary
           new_tap_user, new_tap_repo, = new_tap_name.split("/")
           new_tap_name = "#{new_tap_user}/#{new_tap_repo}"
           new_tap = Tap.fetch new_tap_name
-          new_tap.install unless new_tap.installed?
+          new_tap.ensure_installed!
           new_tapped_name = "#{new_tap_name}/#{name}"
           name, path = formula_name_path(new_tapped_name, warn: false)
           old_name = tapped_name