test-help: improve test coverage

Adds a test for commands without help text.

Extends test coverage of commands.help_ by 1 line.

tests/test-help

@@ -27,4 +27,25 b' hg -q help status'
 hg help foo
 hg skjdfks
 
+cat > helpext.py <<EOF
+import os
+from mercurial import commands
+
+def nohelp(ui, *args, **kwargs):
+    pass
+
+cmdtable = {
+    "nohelp": (nohelp, [], "hg nohelp"),
+}
+
+commands.norepo += ' nohelp'
+EOF
+abspath=`pwd`/helpext.py
+
+echo '[extensions]' >> $HGRCPATH
+echo "helpext = $abspath" >> $HGRCPATH
+
+echo %% test command with no help text
+hg help nohelp
+
 exit 0

tests/test-help.out

@@ -462,3 +462,9 b' basic commands:'
  update     update working directory
 
 use "hg help" for the full list of commands or "hg -v" for details
+%% test command with no help text
+hg nohelp
+
+(no help text available)
+
+use "hg -v help nohelp" to show global options