[PodTarget] Add compatible header search paths for pods with header mappings dirs

lib/cocoapods/installer/xcode/pods_project_generator/file_references_installer.rb

@@ -312,6 +312,7 @@ module Pod
           #
           def header_mappings(headers_sandbox, file_accessor, headers, visibility_scope = :private)
             consumer = file_accessor.spec_consumer
+            header_mappings_dir = consumer.header_mappings_dir
             dir = headers_sandbox
             dir += headers_sandbox if visibility_scope == :public
             dir += consumer.header_dir if consumer.header_dir
@@ -319,9 +320,8 @@ module Pod
             mappings = {}
             headers.each do |header|
               sub_dir = dir
-              if consumer.header_mappings_dir
-                header_mappings_dir = file_accessor.path_list.root + consumer.header_mappings_dir
-                relative_path = header.relative_path_from(header_mappings_dir)
+              if header_mappings_dir
+                relative_path = header.relative_path_from(file_accessor.path_list.root + header_mappings_dir)
                 sub_dir += relative_path.dirname
               end
               mappings[sub_dir] ||= []

lib/cocoapods/target/pod_target.rb

@@ -585,16 +585,33 @@ module Pod
     #
     def header_search_paths(include_test_dependent_targets = false)
       header_search_paths = []
-      header_search_paths.concat(build_headers.search_paths(platform, nil, defines_module?))
-      header_search_paths.concat(sandbox.public_headers.search_paths(platform, pod_name, defines_module?))
+      header_search_paths.concat(build_headers.search_paths(platform, nil, uses_modular_headers?))
+      header_search_paths.concat(sandbox.public_headers.search_paths(platform, pod_name, uses_modular_headers?))
       dependent_targets = recursive_dependent_targets
       dependent_targets += recursive_test_dependent_targets if include_test_dependent_targets
       dependent_targets.each do |dependent_target|
-        header_search_paths.concat(sandbox.public_headers.search_paths(platform, dependent_target.pod_name, defines_module?))
+        header_search_paths.concat(sandbox.public_headers.search_paths(platform, dependent_target.pod_name, defines_module? && dependent_target.uses_modular_headers?(false)))
       end
       header_search_paths.uniq
     end
 
+    protected
+
+    # Returns whether the pod target should use modular headers.
+    #
+    # @param  [Boolean] only_if_defines_modules
+    #         whether the use of modular headers should require the target to define a module
+    #
+    # @note  This must return false when a pod has a `header_mappings_dir`,
+    #        as that allows the spec to completely customize the header structure, and
+    #        therefore it might not be expecting the module name to be prepended
+    #        to imports at all.
+    #
+    def uses_modular_headers?(only_if_defines_modules = true)
+      return false if only_if_defines_modules && !defines_module?
+      spec_consumers.none?(&:header_mappings_dir)
+    end
+
     private
 
     # @param  [TargetDefinition] target_definition

spec/unit/generator/xcconfig/pod_xcconfig_spec.rb

@@ -11,6 +11,7 @@ module Pod
 
             vspec = stub(:test_specification? => false)
             consumer = stub(
+              "Spec Consumer (#{vspec} iOS)",
               :pod_target_xcconfig => {},
               :libraries => ['xml2'],
               :frameworks => [],
@@ -18,6 +19,7 @@ module Pod
               :platform_name => :ios,
             )
             file_accessor = stub(
+              'File Accessor',
               :spec => vspec,
               :spec_consumer => consumer,
               :vendored_static_frameworks => [config.sandbox.root + 'AAA/StaticFramework.framework'],
@@ -26,6 +28,7 @@ module Pod
               :vendored_dynamic_libraries => [config.sandbox.root + 'DDD/VendoredDyld.dyld'],
             )
             vendored_dep_target = stub(
+              'Vendored Dependent Target',
               :name => 'BananaLib',
               :pod_name => 'BananaLib',
               :sandbox => config.sandbox,
@@ -34,6 +37,7 @@ module Pod
               :static_framework? => false,
               :dependent_targets => [],
               :file_accessors => [file_accessor],
+              :uses_modular_headers? => false,
             )
 
             @spec = fixture_spec('banana-lib/BananaLib.podspec')