patch to improve behavior of zdiff when file is compressed without extension

[debian/gzip] / zdiff.in

diff --git a/zdiff.in b/zdiff.in
index 9d3b4aed0a1bd842b84a1b7e71ba2fa987d367af..506a888ef2d78390d9d6e8eec497b63c37d673a5 100644 (file)
--- a/zdiff.in
+++ b/zdiff.in
@@ -76,9 +76,15 @@ gzip_status=0
 exec 3>&1
 
 if test $# -eq 1; then
-  case $1 in
-  *[-.]gz* | *[-.][zZ] | *.t[ga]z)
+  type_file=$(file -b --mime-type "$1")
+
+  case $type_file in
+  application/x-gzip | application/x-compress)
     FILE=`expr "X$1" : 'X\(.*\)[-.][zZtga]*$'`
+    if test "$FILE" == ""; then
+        FILE="$1"
+    fi;
+    
     gzip_status=$(
       exec 4>&1
       (gzip -cd -- "$1" 4>&-; echo $? >&4) 3>&- | eval "$cmp" - '"$FILE"' >&3
@@ -88,10 +94,13 @@ if test $# -eq 1; then
     exit 2;;
   esac
 elif test $# -eq 2; then
-       case "$1" in
-       *[-.]gz* | *[-.][zZ] | *.t[ga]z | -)
-                case "$2" in
-               *[-.]gz* | *[-.][zZ] | *.t[ga]z | -)
+       type_file1=$(file -b --mime-type "$1")
+       type_file2=$(file -b --mime-type "$2")
+       
+       case "$type_file1" in
+       application/x-gzip | application/x-compress)
+                case "$type_file2" in
+               application/x-gzip | application/x-compress)
                    if test "$1$2" = --; then
                        gzip_status=$(
                          exec 4>&1
@@ -118,6 +127,9 @@ elif test $# -eq 2; then
                        (exit $cmp_status)
                    else
                        F=`expr "/$2" : '.*/\(.*\)[-.][zZtga]*$'` || F=$prog
+                       if test "$F" == ""; then
+                           F="$2"
+                       fi;
                        tmp=
                        trap '
                          test -n "$tmp" && rm -f "$tmp"
@@ -147,8 +159,8 @@ elif test $# -eq 2; then
                        eval "$cmp" - '"$2"' >&3
                    );;
                 esac;;
-        *)      case "$2" in
-               *[-.]gz* | *[-.][zZ] | *.t[ga]z | -)
+        *)      case "$type_file2" in
+               application/x-gzip | application/x-compress)
                        gzip_status=$(
                          exec 4>&1
                          (gzip -cdfq -- "$2" 4>&-; echo $? >&4) 3>&- |