config: exit non zero on non-existent config option (issue4247)

When running 'hg config no_such_option', hg exited with a
zero exit code. This change now exits with a 1 if the
config option does not exist.

mercurial/commands.py

@@ -1498,7 +1498,7 b' def config(ui, repo, *values, **opts):'
 
     See :hg:`help config` for more information about config files.
 
-    Returns 0 on success.
+    Returns 0 on success, 1 if NAME does not exist.
 
     """
 
@@ -1551,6 +1551,7 b' def config(ui, repo, *values, **opts):'
         items = [v for v in values if '.' in v]
         if len(items) > 1 or items and sections:
             raise util.Abort(_('only one config item permitted'))
+    matched = False
     for section, name, value in ui.walkconfig(untrusted=untrusted):
         value = str(value).replace('\n', '\\n')
         sectname = section + '.' + name
@@ -1560,14 +1561,20 b' def config(ui, repo, *values, **opts):'
                     ui.debug('%s: ' %
                              ui.configsource(section, name, untrusted))
                     ui.write('%s=%s\n' % (sectname, value))
+                    matched = True
                 elif v == sectname:
                     ui.debug('%s: ' %
                              ui.configsource(section, name, untrusted))
                     ui.write(value, '\n')
+                    matched = True
         else:
             ui.debug('%s: ' %
                      ui.configsource(section, name, untrusted))
             ui.write('%s=%s\n' % (sectname, value))
+            matched = True
+    if matched:
+        return 0
+    return 1
 
 @command('copy|cp',
     [('A', 'after', None, _('record a copy that has already occurred')),

tests/test-config.t

@@ -42,3 +42,8 b' Test "%unset"'
 
   $ hg showconfig unsettest
   unsettest.set-after-unset=should be set (.hg/hgrc)
+
+Test exit code when no config matches
+
+  $ hg config Section.idontexist
+  [1]

tests/test-lfconvert.t

@@ -326,6 +326,7 b' process.'
   verified existence of 6 revisions of 4 largefiles
   [1]
   $ hg -R largefiles-repo-hg showconfig paths
+  [1]
 
 
 Avoid a traceback if a largefile isn't available (issue3519)