From b1f9cb96d4b2924edacbcab569e1b9f37af6e691 Mon Sep 17 00:00:00 2001
From: Erem Boto <erem@citizen.vc>
Date: Sat, 15 Oct 2016 18:21:12 -0700
Subject: [PATCH] Add support for property absence directives in profile
 activation

---
 .../main/scala/coursier/core/Resolution.scala  | 18 +++++++++++-------
 .../scala/coursier/test/ResolutionTests.scala  |  6 ++++++
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/core/shared/src/main/scala/coursier/core/Resolution.scala b/core/shared/src/main/scala/coursier/core/Resolution.scala
index 66cf5169b..f45c3bc4a 100644
--- a/core/shared/src/main/scala/coursier/core/Resolution.scala
+++ b/core/shared/src/main/scala/coursier/core/Resolution.scala
@@ -258,7 +258,7 @@ object Resolution {
           if (mgmtDep.optional)
             dep = dep.copy(optional = mgmtDep.optional)
         }
-        
+
         (config, dep)
       }
   }
@@ -448,12 +448,16 @@ object Resolution {
     activation.properties.nonEmpty &&
       activation.properties.forall {
         case (name, valueOpt) =>
-          props.get(name).exists { v =>
-            valueOpt.forall { reqValue =>
-              if (reqValue.startsWith("!"))
-                v != reqValue.drop(1)
-              else
-                v == reqValue
+          if (name.startsWith("!")) {
+            props.get(name.drop(1)).isEmpty
+          } else {
+            props.get(name).exists { v =>
+              valueOpt.forall { reqValue =>
+                if (reqValue.startsWith("!"))
+                  v != reqValue.drop(1)
+                else
+                  v == reqValue
+              }
             }
           }
       }
diff --git a/tests/shared/src/test/scala/coursier/test/ResolutionTests.scala b/tests/shared/src/test/scala/coursier/test/ResolutionTests.scala
index 8e6a89c67..7ed092605 100644
--- a/tests/shared/src/test/scala/coursier/test/ResolutionTests.scala
+++ b/tests/shared/src/test/scala/coursier/test/ResolutionTests.scala
@@ -155,6 +155,12 @@ object ResolutionTests extends TestSuite {
       // the property "special" is unset. Because that is the case here,
       // the "default" build profile should be active and "librairie-standard"
       // should be provided as a transitive dependency when resolved.
+      //
+      // We additionally include the property "!special" -> "true" to
+      // disambiguate the absence of the "special" property versus
+      // the presence of the "!special" property (which is probably not valid pom
+      // anyways)
+      properties = Seq("!special" -> "true"),
       profiles = Seq(
         Profile("default", activation = Profile.Activation(properties = Seq("!special" -> None)), dependencies = Seq(
           "" -> Dependency(Module("org.escalier", "librairie-standard"), "2.11.6"))))),