--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-06-13  Bruno Haible  <bruno@clisp.org>
+
+	gnulib-tool: Allow comments in the 'Depends-on' section.
+	* doc/gnulib.texi (Module description): Mention comment syntax in the
+	Depends-on section.
+	* gnulib-tool (func_get_dependencies): Filter out comment lines.
+
 2011-06-13  Bruno Haible  <bruno@clisp.org>
 
 	file-set.h: guard __attibute__ use, now that it's not always defined

--- a/doc/gnulib.texi
+++ b/doc/gnulib.texi
@@ -406,6 +406,8 @@
 strtoull   [test $ac_cv_func_strtoumax = no]
 @end smallexample
 
+Lines starting with @code{#} are recognized as comments and are ignored.
+
 @item configure.ac-early
 This field contains @file{configure.ac} stuff (Autoconf macro invocations and
 shell statements) that are logically placed early in the @file{configure.ac}

--- a/gnulib-tool
+++ b/gnulib-tool
@@ -2096,24 +2096,26 @@
       ;;
   esac
   # Then the explicit dependencies listed in the module description.
-  if ! $modcache; then
-    func_lookup_file "modules/$1"
-    sed -n -e "/^Depends-on$sed_extract_prog" < "$lookedup_file"
-  else
-    func_cache_lookup_module "$1"
-    # Output the field's value, including the final newline (if any).
-    if $have_associative; then
-      if eval 'test -n "${modcache_dependson[$1]+set}"'; then
-        eval 'echo "${modcache_dependson[$1]}"'
-      fi
+  { if ! $modcache; then
+      func_lookup_file "modules/$1"
+      sed -n -e "/^Depends-on$sed_extract_prog" < "$lookedup_file"
     else
-      eval "field_set=\"\$${cachevar}_dependson_set\""
-      if test -n "$field_set"; then
-        eval "field_value=\"\$${cachevar}_dependson\""
-        echo "${field_value}"
+      func_cache_lookup_module "$1"
+      # Output the field's value, including the final newline (if any).
+      if $have_associative; then
+        if eval 'test -n "${modcache_dependson[$1]+set}"'; then
+          eval 'echo "${modcache_dependson[$1]}"'
+        fi
+      else
+        eval "field_set=\"\$${cachevar}_dependson_set\""
+        if test -n "$field_set"; then
+          eval "field_value=\"\$${cachevar}_dependson\""
+          echo "${field_value}"
+        fi
       fi
     fi
-  fi
+  } \
+  | sed -e '/^#/d'
 }
 
 # func_get_autoconf_early_snippet module