[gnome-software] Try to work out if an application is free software

[Richard Hughes <rhughes src gnome org>]

commit f5ae21816b29365a6815533427bd38ada0f07cdf
Author: Richard Hughes <richard hughsie com>
Date:   Wed Dec 9 11:06:18 2015 +0000

    Try to work out if an application is free software
    
    The way we're doing this is checking that all parts of the license string are
    SPDX tokens. This isn't ideal as there is a mismatch between common distros
    like Fedora and SPDX, but it's what SUSE and Debian are doing (and AppStream!)
    and seems to be a good distro-neutral way of doing this.

 src/gs-app.c |   41 +++++++++++++++++++++++++++++++++++++++++
 src/gs-app.h |    1 +
 2 files changed, 42 insertions(+), 0 deletions(-)
---
diff --git a/src/gs-app.c b/src/gs-app.c
index cbfbaba..49453b8 100644
--- a/src/gs-app.c
+++ b/src/gs-app.c
@@ -102,6 +102,7 @@ struct _GsApp
        gboolean                 to_be_installed;
        gboolean                 provenance;
        AsBundle                *bundle;
+       gboolean                 licence_is_free;
 };
 
 enum {
@@ -1285,6 +1286,36 @@ gs_app_get_licence (GsApp *app)
 }
 
 /**
+ * gs_app_get_licence_is_free:
+ */
+gboolean
+gs_app_get_licence_is_free (GsApp *app)
+{
+       g_return_val_if_fail (GS_IS_APP (app), FALSE);
+       return app->licence_is_free;
+}
+
+/**
+ * gs_app_get_licence_token_is_nonfree:
+ */
+static gboolean
+gs_app_get_licence_token_is_nonfree (const gchar *token)
+{
+       /* grammar */
+       if (g_strcmp0 (token, "(") == 0)
+               return FALSE;
+       if (g_strcmp0 (token, ")") == 0)
+               return FALSE;
+
+       /* a token, but still nonfree */
+       if (g_strcmp0 (token, "@LicenseRef-proprietary") == 0)
+               return TRUE;
+
+       /* if it has a prefix, assume it is free */
+       return token[0] != '@';
+}
+
+/**
  * gs_app_set_licence:
  */
 void
@@ -1301,6 +1332,9 @@ gs_app_set_licence (GsApp *app, const gchar *licence, GsAppQuality quality)
 
        g_return_if_fail (GS_IS_APP (app));
 
+       /* assume free software until we find an unmatched SPDX token */
+       app->licence_is_free = TRUE;
+
        /* tokenize the license string and URLify any SPDX IDs */
        urld = g_string_sized_new (strlen (licence) + 1);
        tokens = as_utils_spdx_license_tokenize (licence);
@@ -1324,6 +1358,13 @@ gs_app_set_licence (GsApp *app, const gchar *licence, GsAppQuality quality)
                        continue;
                }
 
+               /* do the best we can */
+               if (gs_app_get_licence_token_is_nonfree (tokens[i])) {
+                       g_debug ("nonfree licence from %s: '%s'",
+                                gs_app_get_id (app), tokens[i]);
+                       app->licence_is_free = FALSE;
+               }
+
                /* legacy literal text */
                if (g_str_has_prefix (tokens[i], "#")) {
                        g_string_append (urld, tokens[i] + 1);
diff --git a/src/gs-app.h b/src/gs-app.h
index e281533..233809d 100644
--- a/src/gs-app.h
+++ b/src/gs-app.h
@@ -166,6 +166,7 @@ void                 gs_app_set_url                 (GsApp          *app,
                                                 AsUrlKind       kind,
                                                 const gchar    *url);
 const gchar    *gs_app_get_licence             (GsApp          *app);
+gboolean        gs_app_get_licence_is_free     (GsApp          *app);
 void            gs_app_set_licence             (GsApp          *app,
                                                 const gchar    *licence,
                                                 GsAppQuality    quality);