File bzip2-1.0.6-bzgrep_return_value.patch of Package bzip2.2333

Index: bzip2-1.0.6/bzgrep
===================================================================
--- bzip2-1.0.6.orig/bzgrep
+++ bzip2-1.0.6/bzgrep
@@ -67,8 +67,20 @@ for i do
     j=${j//|/\\|}
     j=${j//&/\\&}
     j=`printf "%s" "$j" | tr '\n' ' '`
-    bzip2 -cdfq "$i" | $grep $opt "$pat" | sed "s|^|${j}:|"
-    r=$?
+    # A trick adapted from
+    # https://groups.google.com/forum/#!original/comp.unix.shell/x1345iu10eg/Nn1n-1r1uU0J
+    # that has the same effect as the following bash code:
+    # bzip2 -cdfq "$i" | $grep $opt "$pat" | sed "s|^|${j}:|"
+    # r=${PIPESTATUS[1]}
+    exec 3>&1
+    eval `
+      exec 4>&1 >&3 3>&-
+      {
+        bzip2 -cdfq "$i" 4>&-
+      } | {
+        $grep $opt "$pat" 4>&-; echo "r=$?;" >&4
+      } | sed "s|^|${j}:|"
+    `
   fi
   test "$r" -ne 0 && res="$r"
 done