Add new command line option for hiding gzip metadata from diffoscope output

Hide-gzip-metadata.diff

diff --git a/diffoscope/comparators/gzip.py b/diffoscope/comparators/gzip.py
index fff03e5..876418f 100644
--- a/diffoscope/comparators/gzip.py
+++ b/diffoscope/comparators/gzip.py
@@ -25,6 +25,7 @@ import collections
 from diffoscope import logger, tool_required
 from diffoscope.difference import Difference
 from diffoscope.comparators.utils import Archive, get_compressed_content_name
+from diffoscope.config import Config
 
 
 class GzipContainer(Archive):
@@ -61,3 +62,11 @@ class GzipFile(object):
 
     def compare_details(self, other, source=None):
         return [Difference.from_text(self.magic_file_type, other.magic_file_type, self, other, source='metadata')]
+
+    def compare(self, other, source=None):
+        differences = super().compare(other, source)
+        if differences is None:
+            return None
+        if Config.general.hide_profile == 'metadata' and len(differences.details) == 1 and differences.details[0].source1 == 'metadata':
+            return None
+        return differences
diff --git a/diffoscope/config.py b/diffoscope/config.py
index ff65558..e0387ce 100644
--- a/diffoscope/config.py
+++ b/diffoscope/config.py
@@ -33,6 +33,7 @@ class Config(object):
         self._separate_file_diff_size = 200 * 2 ** 10 # 200kB
         self._fuzzy_threshold = 60
         self._new_file = False
+        self._hide_profile = None
 
     @classproperty
     def general(cls):
@@ -87,3 +88,11 @@ class Config(object):
     @new_file.setter
     def new_file(self, value):
         self._new_file = value
+
+    @property
+    def hide_profile(self):
+        return self._hide_profile
+
+    @hide_profile.setter
+    def hide_profile(self, value):
+        self._hide_profile = value
diff --git a/diffoscope/main.py b/diffoscope/main.py
index 7cd234a..81140b8 100644
--- a/diffoscope/main.py
+++ b/diffoscope/main.py
@@ -102,6 +102,8 @@ def create_parser():
                         help='link to the jquery url, with --html-dir. Specify “disable” to disable JavaScript. When omitted diffoscope will try to create a symlink to a system installation. Known locations: %s' % ', '.join(JQUERY_SYSTEM_LOCATIONS))
     parser.add_argument('path1', help='first file or directory to compare')
     parser.add_argument('path2', help='second file or directory to compare')
+    parser.add_argument('--hide', dest='hide_profile', action='store', choices=['metadata'],
+                        help='Switch to hide profiles from output')
     if not tlsh:
         parser.epilog = 'File renaming detection based on fuzzy-matching is currently disabled. It can be enabled by installing the “tlsh” module available at https://github.com/trendmicro/tlsh'
     if argcomplete:
@@ -170,6 +172,7 @@ def run_diffoscope(parsed_args):
     Config.general.separate_file_diff_size = parsed_args.separate_file_diff_size
     Config.general.fuzzy_threshold = parsed_args.fuzzy_threshold
     Config.general.new_file = parsed_args.new_file
+    Config.general.hide_profile = parsed_args.hide_profile
     if parsed_args.debug:
         logger.setLevel(logging.DEBUG)
     set_locale()
satyam@satyamz:~/debian/satyamz-guest/project/reproducible-builds/59/complete/diffoscope/bin$ git diff
diff --git a/diffoscope/comparators/gzip.py b/diffoscope/comparators/gzip.py
index fff03e5..74711e4 100644
--- a/diffoscope/comparators/gzip.py
+++ b/diffoscope/comparators/gzip.py
@@ -25,6 +25,7 @@ import collections
 from diffoscope import logger, tool_required
 from diffoscope.difference import Difference
 from diffoscope.comparators.utils import Archive, get_compressed_content_name
+from diffoscope.config import Config
 
 
 class GzipContainer(Archive):
@@ -61,3 +62,11 @@ class GzipFile(object):
 
     def compare_details(self, other, source=None):
         return [Difference.from_text(self.magic_file_type, other.magic_file_type, self, other, source='metadata')]
+
+    def compare(self, other, source=None):
+        differences = super().compare(other, source)
+        if differences is None:
+            return None
+        if Config.general.hide_profile == 'gzip-metadata' and differences.details[0].source1 == 'metadata':
+            return None
+        return differences
diff --git a/diffoscope/config.py b/diffoscope/config.py
index ff65558..e0387ce 100644
--- a/diffoscope/config.py
+++ b/diffoscope/config.py
@@ -33,6 +33,7 @@ class Config(object):
         self._separate_file_diff_size = 200 * 2 ** 10 # 200kB
         self._fuzzy_threshold = 60
         self._new_file = False
+        self._hide_profile = None
 
     @classproperty
     def general(cls):
@@ -87,3 +88,11 @@ class Config(object):
     @new_file.setter
     def new_file(self, value):
         self._new_file = value
+
+    @property
+    def hide_profile(self):
+        return self._hide_profile
+
+    @hide_profile.setter
+    def hide_profile(self, value):
+        self._hide_profile = value
diff --git a/diffoscope/main.py b/diffoscope/main.py
index 7cd234a..35a8683 100644
--- a/diffoscope/main.py
+++ b/diffoscope/main.py
@@ -102,6 +102,8 @@ def create_parser():
                         help='link to the jquery url, with --html-dir. Specify “disable” to disable JavaScript. When omitted diffoscope will try to create a symlink to a system installation. Known locations: %s' % ', '.join(JQUERY_SYSTEM_LOCATIONS))
     parser.add_argument('path1', help='first file or directory to compare')
     parser.add_argument('path2', help='second file or directory to compare')
+    parser.add_argument('--hide', dest='hide_profile', action='store', choices=['gzip-metadata'],
+                        help='Switch to hide profiles from output')
     if not tlsh:
         parser.epilog = 'File renaming detection based on fuzzy-matching is currently disabled. It can be enabled by installing the “tlsh” module available at https://github.com/trendmicro/tlsh'
     if argcomplete:
@@ -170,6 +172,7 @@ def run_diffoscope(parsed_args):
     Config.general.separate_file_diff_size = parsed_args.separate_file_diff_size
     Config.general.fuzzy_threshold = parsed_args.fuzzy_threshold
     Config.general.new_file = parsed_args.new_file
+    Config.general.hide_profile = parsed_args.hide_profile
     if parsed_args.debug:
         logger.setLevel(logging.DEBUG)
     set_locale()