maint: update bootstrap from Gnulib

diff --git a/bootstrap b/bootstrap
index 20913180a640e388153a994408bc249b59baae7c..6295b8a128f667ea3f317e04efea28c9be526dca 100755 (executable)
--- a/bootstrap
+++ b/bootstrap
@@ -37,7 +37,7 @@ medir=`dirname "$me"`
 
 # A library of shell functions for autopull.sh, autogen.sh, and bootstrap.
 
-scriptlibversion=2024-04-13.15; # UTC
+scriptlibversion=2024-04-28.09; # UTC
 
 # Copyright (C) 2003-2024 Free Software Foundation, Inc.
 #
@@ -499,7 +499,17 @@ prepare_GNULIB_SRCDIR ()
       || die "Error: --gnulib-srcdir or \$GNULIB_SRCDIR is specified," \
              "but does not contain gnulib-tool"
     if test -n "$GNULIB_REVISION" && $use_git; then
-      (cd "$GNULIB_SRCDIR" && git checkout "$GNULIB_REVISION") || exit $?
+      # The 'git checkout "$GNULIB_REVISION"' command succeeds if the
+      # GNULIB_REVISION is a commit hash that exists locally, or if it is
+      # branch name that can be fetched from origin. It fails, however,
+      # if the GNULIB_REVISION is a commit hash that only exists in
+      # origin. In this case, we need a 'git fetch' and then retry
+      # 'git checkout "$GNULIB_REVISION"'.
+      (cd "$GNULIB_SRCDIR" \
+       && { git checkout "$GNULIB_REVISION" 2>/dev/null \
+            || { git fetch origin && git checkout "$GNULIB_REVISION"; }
+          }
+      ) || exit $?
     fi
   else
     if ! $use_git; then
@@ -569,7 +579,17 @@ prepare_GNULIB_SRCDIR ()
         # The subdirectory 'gnulib' already exists.
         if test -n "$GNULIB_REVISION"; then
           if test -d "$gnulib_path/.git"; then
-            (cd "$gnulib_path" && git checkout "$GNULIB_REVISION") || exit 1
+            # The 'git checkout "$GNULIB_REVISION"' command succeeds if the
+            # GNULIB_REVISION is a commit hash that exists locally, or if it is
+            # branch name that can be fetched from origin. It fails, however,
+            # if the GNULIB_REVISION is a commit hash that only exists in
+            # origin. In this case, we need a 'git fetch' and then retry
+            # 'git checkout "$GNULIB_REVISION"'.
+            (cd "$gnulib_path" \
+             && { git checkout "$GNULIB_REVISION" 2>/dev/null \
+                  || { git fetch origin && git checkout "$GNULIB_REVISION"; }
+                }
+            ) || exit $?
           else
             die "Error: GNULIB_REVISION is specified in bootstrap.conf," \
                 "but '$gnulib_path' contains no git history"