[Buildroot] [PATCH] apply-patches.sh: detect missing patches

[Ralph Siemsen <ralphs@netwinder.org>]

apply-patches.sh: detect missing patches

The current patch logic does not detect missing patch files,
particularly when using a series file. If the series file
refers to non-existent patches, a minor warning appears,
but the build continues.

The root cause is the "cat <patchfile> | patch ..." pipleline.
When patchfile does not exist, the "cat" command prints a
warning, however, the pipeline status is determined by the
final "patch" command. And since patch has not received any
input, it returns success.

There are two possible solutions that I can see:
  1. set -o pipefail, then pipeline will return error from 'cat'
  2. check for patch existence explicitly
I've opted for 2nd choice, it seems less risky.

The following patch adds the check. It also fixes the indentation
of an adjacent line (TAB versus spaces) making it consistent.

diff --git a/support/scripts/apply-patches.sh b/support/scripts/apply-patches.sh
index 7d5856c..a3f7153 100755
--- a/support/scripts/apply-patches.sh
+++ b/support/scripts/apply-patches.sh
@@ -76,7 +76,11 @@ function apply_patch {
     esac
     echo ""
     echo "Applying $patch using ${type}: "
-	echo $patch >> ${builddir}/.applied_patches_list
+    if ! test -e "${path}/$patch" ; then
+	echo "Error: missing patch file ${path}/$patch"
+	return 1
+    fi
+    echo $patch >> ${builddir}/.applied_patches_list
     ${uncomp} "${path}/$patch" | patch -g0 -p1 -E -d "${builddir}"
     if [ $? != 0 ] ; then
         echo "Patch failed!  Please fix ${patch}!"