configure: Maintainer mode requires imagemagick.

Make.rules.in

@@ -48,6 +48,7 @@ LINT      = @LINT@
 LINTFLAGS = @LINTFLAGS@
 FONTFORGE = @FONTFORGE@
 RSVG      = @RSVG@
+CONVERT   = @CONVERT@
 ICOTOOL   = @ICOTOOL@
 CROSSCC   = @CROSSCC@
 CROSSTARGET = @CROSSTARGET@

configure

@@ -671,6 +671,7 @@ OPENGL_LIBS
 XLIB
 PRELINK
 ICOTOOL
+CONVERT
 RSVG
 PKG_CONFIG
 FONTFORGE
@@ -5020,6 +5021,49 @@ fi
 done
 test -n "$RSVG" || RSVG="false"
 
+for ac_prog in convert
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if test "${ac_cv_prog_CONVERT+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$CONVERT"; then
+  ac_cv_prog_CONVERT="$CONVERT" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_CONVERT="$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+CONVERT=$ac_cv_prog_CONVERT
+if test -n "$CONVERT"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CONVERT" >&5
+$as_echo "$CONVERT" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+  test -n "$CONVERT" && break
+done
+test -n "$CONVERT" || CONVERT="false"
+
 for ac_prog in icotool
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
@@ -5068,6 +5112,7 @@ if test "${enable_maintainer_mode+set}" = set
 then
   if test "$FONTFORGE" = "false"; then as_fn_append wine_warnings "|fontforge is missing, fonts can't be rebuilt."; fi
   if test "$RSVG" = "false"; then as_fn_append wine_warnings "|rsvg is missing, icons can't be rebuilt."; fi
+  if test "$CONVERT" = "false"; then as_fn_append wine_warnings "|imagemagick is missing, icons can't be rebuilt."; fi
 
     if test "$ICOTOOL" = false
   then

configure.ac

@@ -281,12 +281,14 @@ dnl Check for various programs
 AC_CHECK_PROGS(FONTFORGE, fontforge, false)
 AC_CHECK_PROGS(PKG_CONFIG, pkg-config, false)
 AC_CHECK_PROGS(RSVG, rsvg, false)
+AC_CHECK_PROGS(CONVERT, convert, false)
 AC_CHECK_PROGS(ICOTOOL, icotool, false)
 
 if test "${enable_maintainer_mode+set}" = set
 then
   if test "$FONTFORGE" = "false"; then WINE_WARNING([fontforge is missing, fonts can't be rebuilt.]); fi
   if test "$RSVG" = "false"; then WINE_WARNING([rsvg is missing, icons can't be rebuilt.]); fi
+  if test "$CONVERT" = "false"; then WINE_WARNING([imagemagick is missing, icons can't be rebuilt.]); fi
 
   dnl Check the icotool version
   if test "$ICOTOOL" = false