gnulib-tool should be interruptible

[Ralf Wildenhues]

Right now, hitting ^C will make a running gnulib-tool go rather wild;
in any case, it won't make it stop consistently.  I propose an approach
like in Autoconf-generated scripts, see below.  Also I think a SIGPIPE
caused by a write error should be caught as well.

Cheers,
Ralf

        * gnulib-tool (func_exit): New function, to allow to pass the
        exit status portably through the trap.  Use everywhere.
        (--help, --version): Signal a write error.
        (trap): catch SIGPIPE, for write errors.
        Exit at the end of the trap, with the correct exit status.

Index: gnulib-tool
===================================================================
RCS file: /cvsroot/gnulib/gnulib/gnulib-tool,v
retrieving revision 1.160
diff -u -r1.160 gnulib-tool
--- gnulib-tool 13 Sep 2006 15:00:47 -0000      1.160
+++ gnulib-tool 16 Sep 2006 07:05:50 -0000
@@ -177,6 +177,13 @@
   echo "# Generated by gnulib-tool."
 }
 
+# func_exit STATUS
+# exit with status
+func_exit ()
+{
+  (exit $1); exit $1
+}
+
 # func_tmpdir
 # creates a temporary directory.
 # Sets variable
@@ -204,7 +211,7 @@
   } ||
   {
     echo "$0: cannot create a temporary directory in $TMPDIR" >&2
-    { (exit 1); exit 1; }
+    func_exit 1
   }
 }
 
@@ -214,7 +221,7 @@
 {
   echo "gnulib-tool: *** $1" 1>&2
   echo "gnulib-tool: *** Stop." 1>&2
-  exit 1
+  func_exit 1
 }
 
 # func_readlink SYMLINK
@@ -548,10 +555,10 @@
         shift ;;
       --help | --hel | --he | --h )
         func_usage
-        exit 0 ;;
+        func_exit $? ;;
       --version | --versio | --versi | --vers | --ver | --ve | --v )
         func_version
-        exit 0 ;;
+        func_exit $? ;;
       -- )
         # Stop option processing
         shift
@@ -559,7 +566,7 @@
       -* )
         echo "gnulib-tool: unknown option $1" 1>&2
         echo "Try 'gnulib-tool --help' for more information." 1>&2
-        exit 1 ;;
+        func_exit 1 ;;
       * )
         break ;;
     esac
@@ -571,7 +578,7 @@
       echo "Try 'gnulib-tool --help' for more information." 1>&2
       echo "If you really want to modify the gnulib configuration of your 
project," 1>&2
       echo "you need to use 'gnulib --import' - at your own risk!" 1>&2
-      exit 1
+      func_exit 1
     fi
     if test -n "$local_gnulib_dir" || test -n "$supplied_libname" \
        || test -n "$sourcebase" || test -n "$m4base" \
@@ -582,7 +589,7 @@
       echo "Try 'gnulib-tool --help' for more information." 1>&2
       echo "If you really want to modify the gnulib configuration of your 
project," 1>&2
       echo "you need to use 'gnulib --import' - at your own risk!" 1>&2
-      exit 1
+      func_exit 1
     fi
     do_changelog=false
   fi
@@ -685,7 +692,16 @@
 gnulib_dir=`echo "$self_abspathname" | sed -e 's,/[^/]*$,,'`
 
 func_tmpdir
-trap 'rm -rf "$tmp"' 0 1 2 3 15
+trap 'exit_status=$?
+      if test "$signal" != 0; then
+        echo "caught signal $signal" >&2
+      fi
+      rm -rf "$tmp"
+      exit $exit_status' 0
+for signal in 1 2 3 13 15; do
+  trap '{ signal='$signal'; func_exit 1; }' $signal
+done
+signal=0
 
 # func_lookup_file file
 # looks up a file in $local_gnulib_dir or $gnulib_dir, or combines it through
@@ -2498,7 +2514,7 @@
               #   local_gnulib_dir, avoidlist, sourcebase, m4base, docbase,
               #   testsbase, libname, lgpl, makefile_name, libtool, 
macro_prefix
               # don't propagate from one directory to another.
-              (func_import) || exit 1
+              (func_import) || func_exit 1
             done
           else
             # Really ambiguous.
@@ -2545,7 +2561,7 @@
         if test -n "$remaining"; then
           echo "Remaining files:" $remaining 1>&2
           echo "gnulib-tool: *** Stop." 1>&2
-          exit 1
+          func_exit 1
         fi
       cd ..
     cd ..
@@ -2568,7 +2584,7 @@
         if test -n "$remaining"; then
           echo "Remaining files:" $remaining 1>&2
           echo "gnulib-tool: *** Stop." 1>&2
-          exit 1
+          func_exit 1
         fi
       cd ..
     cd ..
@@ -2671,12 +2687,12 @@
 
 rm -rf "$tmp"
 # Undo the effect of the previous 'trap' command. Some shellology:
-# We cannot use "trap - 0 1 2 3 15", because Solaris sh would attempt to
+# We cannot use "trap - 0 1 2 3 13 15", because Solaris sh would attempt to
 # execute the command "-". "trap '' ..." is fine only for signal 0 (= normal
 # exit); for the others we need to call 'exit' explicitly. The value of $? is
 # 128 + signal number and is set before the trap-registered command is run.
 trap '' 0
-trap 'exit $?' 1 2 3 15
+trap 'func_exit $?' 1 2 3 13 15
 
 exit 0