Recursively expand requirements in FormulaInstaller

Currently FormulaInstaller "forgets" about the requirements of
dependencies, as dependencies are recursively expanded by the first
FormulaInstaller instance, and then ignored by subsequent instances to
prevent duplicate installation attempts. These requirements then have
their messages displayed, but the fatal check is skipped and thus no
exception is raised.

Now that we have Formula#recursive_requirements, we can mirror what we
are doing with dependencies and recursively expand requirements up
front.

While at it, fix a bug in determining Requirement equality that resulted
in unique requirements being eliminated from a formula's set of
recursive requirements.

Fixes Homebrew/homebrew#12290.
Fixes Homebrew/homebrew#14084.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

1 files changed, 6 insertions, 18 deletions

diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 97ab036f6..8e8770db7 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -66,26 +66,14 @@ class FormulaInstaller
       EOS
     end
 
-    # Build up a list of unsatisifed fatal requirements
-    first_message = true
-    unsatisfied_fatals = []
-    f.requirements.each do |req|
-      unless req.satisfied?
-        # Newline between multiple messages
-        puts unless first_message
-        puts req.message
-        first_message = false
-        if req.fatal? and not ignore_deps
-          unsatisfied_fatals << req
-        end
+    unless ignore_deps
+      needed_reqs = f.recursive_requirements.reject { |r| r.satisfied? }
+      puts needed_reqs.map { |r| r.message } * "\n"
+      unsatisfied_fatals = needed_reqs.select { |r| r.fatal? }
+      unless unsatisfied_fatals.empty?
+        raise UnsatisfiedRequirements.new(f, unsatisfied_fatals)
       end
-    end
 
-    unless unsatisfied_fatals.empty?
-      raise UnsatisfiedRequirements.new(f, unsatisfied_fatals)
-    end
-
-    unless ignore_deps
       needed_deps = f.recursive_deps.reject{ |d| d.installed? }
       unless needed_deps.empty?
         needed_deps.each do |dep|