Add hooks/pre-commit.hook

meson.build in gstreamer-vaapi requires hooks/pre-commit.hook

Copied and pasted pre-commit.hook from other gstreamer modules to make
sure gstreamer-vaapi follows the same code style

hooks/pre-commit.hook

@@ -0,0 +1,83 @@
+#!/bin/sh
+#
+# Check that the code follows a consistent code style
+#
+
+# Check for existence of indent, and error out if not present.
+# On some *bsd systems the binary seems to be called gnunindent,
+# so check for that first.
+
+version=`gnuindent --version 2>/dev/null`
+if test "x$version" = "x"; then
+  version=`gindent --version 2>/dev/null`
+  if test "x$version" = "x"; then
+    version=`indent --version 2>/dev/null`
+    if test "x$version" = "x"; then
+      echo "GStreamer git pre-commit hook:"
+      echo "Did not find GNU indent, please install it before continuing."
+      exit 1
+    else
+      INDENT=indent
+    fi
+  else
+    INDENT=gindent
+  fi
+else
+  INDENT=gnuindent
+fi
+
+case `$INDENT --version` in
+  GNU*)
+      ;;
+  default)
+      echo "GStreamer git pre-commit hook:"
+      echo "Did not find GNU indent, please install it before continuing."
+      echo "(Found $INDENT, but it doesn't seem to be GNU indent)"
+      exit 1
+      ;;
+esac
+
+INDENT_PARAMETERS="--braces-on-if-line \
+	--case-brace-indentation0 \
+	--case-indentation2 \
+	--braces-after-struct-decl-line \
+	--line-length80 \
+	--no-tabs \
+	--cuddle-else \
+	--dont-line-up-parentheses \
+	--continuation-indentation4 \
+	--honour-newlines \
+	--tab-size8 \
+	--indent-level2 \
+	--leave-preprocessor-space"
+
+echo "--Checking style--"
+for file in `git diff-index --cached --name-only HEAD --diff-filter=ACMR| grep "\.c$"` ; do
+    # nf is the temporary checkout. This makes sure we check against the
+    # revision in the index (and not the checked out version).
+    nf=`git checkout-index --temp ${file} | cut -f 1`
+    newfile=`mktemp /tmp/${nf}.XXXXXX` || exit 1
+    $INDENT ${INDENT_PARAMETERS} \
+	$nf -o $newfile 2>> /dev/null
+    # FIXME: Call indent twice as it tends to do line-breaks
+    # different for every second call.
+    $INDENT ${INDENT_PARAMETERS} \
+        $newfile 2>> /dev/null
+    diff -u -p "${nf}" "${newfile}"
+    r=$?
+    rm "${newfile}"
+    rm "${nf}"
+    if [ $r != 0 ] ; then
+echo "================================================================================================="
+echo " Code style error in: $file                                                                      "
+echo "                                                                                                 "
+echo " Please fix before committing. Don't forget to run git add before trying to commit again.        "
+echo " If the whole file is to be committed, this should work (run from the top-level directory):      "
+echo "                                                                                                 "
+echo "   gst-indent $file; git add $file; git commit"
+echo "                                                                                                 "
+echo "================================================================================================="
+        exit 1
+    fi
+done
+echo "--Checking style pass--"