[PATCH pinentry] Qt: Make sure extended grep is used with '|'.

[Raphael Kubo da Costa]

* m4/qt.m4: Use grep -E when using the alternation character.
--

POSIX specifies '|' is only supposed to work as an alternation special
character when grep is used in extended mode. The code worked fine
with GNU grep because it accepts extended regular expressions by
default, but other POSIX-compliant implementations might fail and take
it literally.

Signed-off-by: Raphael Kubo da Costa <rakuco at FreeBSD.org>
---
 m4/qt.m4 | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/m4/qt.m4 b/m4/qt.m4
index 90c4a6e..35d9ae2 100644
--- a/m4/qt.m4
+++ b/m4/qt.m4
@@ -60,18 +60,18 @@ AC_DEFUN([FIND_QT],
     AC_CHECK_TOOL(MOC, moc)
     AC_MSG_CHECKING([moc version])
     mocversion=`$MOC -v 2>&1`
-    mocversiongrep=`echo $mocversion | grep "Qt 5\|moc 5"`
+    mocversiongrep=`echo $mocversion | grep -E "Qt 5|moc 5"`
     if test x"$mocversiongrep" != x"$mocversion"; then
       AC_MSG_RESULT([no])
       # moc was not the qt5 one, try with moc-qt5
       AC_CHECK_TOOL(MOC2, moc-qt5)
       mocversion=`$MOC2 -v 2>&1`
-      mocversiongrep=`echo $mocversion | grep "Qt 5\|moc-qt5 5\|moc 5"`
+      mocversiongrep=`echo $mocversion | grep -E "Qt 5|moc-qt5 5|moc 5"`
       if test x"$mocversiongrep" != x"$mocversion"; then
         AC_CHECK_TOOL(QTCHOOSER, qtchooser)
         qt5tooldir=`QT_SELECT=qt5 qtchooser -print-env | grep QTTOOLDIR | cut -d '=' -f 2 | cut -d \" -f 2`
         mocversion=`$qt5tooldir/moc -v 2>&1`
-        mocversiongrep=`echo $mocversion | grep "Qt 5\|moc 5"`
+        mocversiongrep=`echo $mocversion | grep -E "Qt 5|moc 5"`
         if test x"$mocversiongrep" != x"$mocversion"; then
           # no valid moc found
           have_qt5_libs="no";
-- 
2.11.0