Allow explicit conversion of requirements to deps

Fixes #19857.

1 files changed, 21 insertions, 4 deletions

diff --git a/Library/Homebrew/build.rb b/Library/Homebrew/build.rb
index e59b5be6a..96245f022 100755
--- a/Library/Homebrew/build.rb
+++ b/Library/Homebrew/build.rb
@@ -59,8 +59,10 @@ class Build
 
   def initialize(f)
     @f = f
+    # Expand requirements before dependencies, as requirements
+    # may add dependencies if a default formula is activated.
+    @reqs = expand_reqs
     @deps = expand_deps
-    @reqs = f.recursive_requirements
   end
 
   def post_superenv_hacks
@@ -77,6 +79,19 @@ class Build
       not ARGV.include? '--env=super'
   end
 
+  def expand_reqs
+    f.recursive_requirements do |dependent, req|
+      if (req.optional? || req.recommended?) && dependent.build.without?(req.name)
+        Requirement.prune
+      elsif req.build? && dependent != f
+        Requirement.prune
+      elsif req.satisfied? && req.default_formula? && (dep = req.to_dependency).installed?
+        dependent.deps << dep
+        Requirement.prune
+      end
+    end
+  end
+
   def expand_deps
     f.recursive_dependencies do |dependent, dep|
       if dep.optional? || dep.recommended?
@@ -84,18 +99,18 @@ class Build
       elsif dep.build?
         Dependency.prune unless dependent == f
       end
-    end.map(&:to_formula)
+    end
   end
 
   def install
-    keg_only_deps = deps.select(&:keg_only?)
+    keg_only_deps = deps.map(&:to_formula).select(&:keg_only?)
 
     pre_superenv_hacks
     require 'superenv'
 
     deps.each do |dep|
       opt = HOMEBREW_PREFIX/:opt/dep
-      fixopt(dep) unless opt.directory? or ARGV.ignore_deps?
+      fixopt(dep.to_formula) unless opt.directory? or ARGV.ignore_deps?
     end
 
     if superenv?
@@ -105,9 +120,11 @@ class Build
       ENV.setup_build_environment
       post_superenv_hacks
       reqs.each(&:modify_build_environment)
+      deps.each(&:modify_build_environment)
     else
       ENV.setup_build_environment
       reqs.each(&:modify_build_environment)
+      deps.each(&:modify_build_environment)
 
       keg_only_deps.each do |dep|
         opt = dep.opt_prefix