m4: test_with.m4 - Modernize m4 syntax

- Use AS_IF macro instead of plain `if`/`elif`/`then`/`else`/`fi`,
- rewrite path-test to improve readability.

diff --git a/m4/test_with.m4 b/m4/test_with.m4
index 85a99c1d0ddd674a14fd08133a828d23ac3cc691..8a22a6970ae14e19529575e51ec3903a1f59886d 100644 (file)
--- a/m4/test_with.m4
+++ b/m4/test_with.m4
@@ -1,18 +1,18 @@
 dnl TEST_WITH(name, value, [plugin])
 AC_DEFUN([TEST_WITH], [
   want=want_`echo $1|sed s/-/_/g`
-  if test $2 = yes || test $2 = no || test $2 = auto; then
+  AS_IF([test "$2" = yes || test "$2" = no || test "$2" = auto], [
     eval $want=$2
-  elif test $2 = plugin; then
-    if test "$3" = plugin; then
+  ], [test "$2" = plugin], [
+    AS_IF([test "$3" = "plugin"], [
       eval $want=plugin
-    else
+    ], [
       AC_ERROR([--with-$1=plugin not supported])
-    fi
-  elif `echo $2|grep '^/' >/dev/null`; then
+    ])
+  ], [test "$(echo $2|grep -c '^/' 2>/dev/null)" -gt 0], [
     AC_ERROR([--with-$1=path not supported. You may want to use instead:
-CPPFLAGS=-I$2/include LDFLAGS=-L$2/lib ./configure --with-$1])
-  else
+CPPFLAGS=-I$2/include LDFLAGS=-L$2/lib ./configure --with-$1)
+  ], [
     AC_ERROR([--with-$1: Unknown value: $2])
-  fi
+  ])
 ])