Remove duplicate packages after resolving requires

Makes the resolved package list be correctly serialized with each
package only appearing once. This provides more consistency between the
various flag outputs by ensuring that the flags from each package are
only grabbed once. This makes a difference since the duplicate flag
stripping happens from the end of the output (-l) or the beginning of
the output (-L/-I/other).

3 files changed, 47 insertions, 5 deletions

diff --git a/check/check-duplicate-flags b/check/check-duplicate-flags
index b1ab54b..c80f650 100755
--- a/check/check-duplicate-flags
+++ b/check/check-duplicate-flags
@@ -6,7 +6,6 @@ set -e
 
 RESULT="-DPATH2 -DFOO -DPATH1 -I/path/include"
 run_test --cflags flag-dup-1 flag-dup-2
-RESULT="-DPATH1 -DFOO -DPATH2 -I/path/include"
 run_test --cflags flag-dup-2 flag-dup-1
 
 RESULT="-Wl,--whole-archive --Wl,--no-whole-archive -Xlinker -R /path/lib \
diff --git a/check/check-gtk b/check/check-gtk
index 9795a5e..3f9aae7 100755
--- a/check/check-gtk
+++ b/check/check-gtk
@@ -14,10 +14,9 @@ PKG_CONFIG_LIBDIR=${srcdir}/gtk
 # -I/gtk/include/glib-2.0 -I/gtk/lib/glib-2.0/include -I/gtk/include/pixman-1 \
 # -I/gtk/include -I/gtk/include/freetype2
 RESULT="-DGSEAL_ENABLE -pthread -I/gtk/include/gtk-3.0 \
--I/gtk/include/pango-1.0 -I/gtk/include -I/gtk/include/freetype2 \
--I/gtk/include/glib-2.0 -I/gtk/lib/glib-2.0/include \
--I/gtk/include/gdk-pixbuf-2.0 -I/gtk/include/cairo -I/gtk/include/pixman-1 \
--I/gtk/include/atk-1.0"
+-I/gtk/include/pango-1.0 -I/gtk/include/atk-1.0 -I/gtk/include/cairo \
+-I/gtk/include/gdk-pixbuf-2.0 -I/gtk/include -I/gtk/include/freetype2 \
+-I/gtk/include/pixman-1 -I/gtk/include/glib-2.0 -I/gtk/lib/glib-2.0/include"
 run_test --cflags gtk+-3.0
 run_test --cflags --static gtk+-3.0
 
diff --git a/pkg.c b/pkg.c
index a6825ce..148b5aa 100644
--- a/pkg.c
+++ b/pkg.c
@@ -671,6 +671,43 @@ merge_flag_lists (GList *packages, GetListFunc func, GList **listp)
     }
 }
 
+/* Work backwards from the end of the package list to remove duplicate
+ * packages. This could happen because the package was specified multiple
+ * times on the command line, or because multiple packages require the same
+ * package. When we have duplicate dependencies, starting from the end of the
+ * list ensures that the dependency shows up later in the package list and
+ * Libs will come out correctly. */
+static GList *
+package_list_strip_duplicates (GList *packages)
+{
+  GList *cur;
+  GHashTable *requires;
+
+  requires = g_hash_table_new (g_str_hash, g_str_equal);
+  for (cur = g_list_last (packages); cur != NULL; cur = g_list_previous (cur))
+    {
+      Package *pkg = cur->data;
+
+      if (g_hash_table_lookup (requires, pkg->key) != NULL)
+        {
+          GList *dup = cur;
+
+          /* Remove the duplicate package from the list */
+          debug_spew ("Removing duplicate package %s\n", pkg->key);
+          cur = cur->next;
+          packages = g_list_delete_link (packages, dup);
+        }
+      else
+        {
+          /* Unique package. Track it and move to the next. */
+          g_hash_table_insert (requires, pkg->key, pkg);
+        }
+    }
+  g_hash_table_destroy (requires);
+
+  return packages;
+}
+
 static void
 fill_list (GList *packages, GetListFunc func,
            GList **listp, gboolean in_path_order, gboolean include_private)
@@ -689,6 +726,13 @@ fill_list (GList *packages, GetListFunc func,
       tmp = tmp->next;
     }
 
+  /* Remove duplicate packages from the recursive list. This should provide a
+   * serialized package list where all interdependencies are resolved
+   * consistently. */
+  spew_package_list (" pre-remove", expanded);
+  expanded = package_list_strip_duplicates (expanded);
+  spew_package_list ("post-remove", expanded);
+
   if (in_path_order)
     {
       spew_package_list ("original", expanded);