+#!/bin/sh
+##########################################################
+# Test incorporating mail from stdin with `inc -file -`. #
+##########################################################
+. "$MH_TEST_COMMON"
+
+# Test empty stdin from a pipe.
+runandcheck "printf '' |inc -file -" <<!
+Incorporating new mail into inbox...
+
+inc: no messages incorporated, continuing...
+!
+
+# Test empty stdin from redirected regular file.
+cd "$MMH_TEST_DIR"
+f=mbox
+runandcheck "printf '' >$f && inc -file - <$f" <<!
+Incorporating new mail into inbox...
+
+inc: no messages incorporated, continuing...
+!
+rm "$f"
+unset f
+
+# Test empty stdin from character device.
+runandcheck "inc -file - </dev/null" <<!
+Incorporating new mail into inbox...
+
+inc: no messages incorporated, continuing...
+!
+
+# Test nonempty pipe.
+runandcheck "packf +inbox |inc -file -" <<!
+Incorporating new mail into inbox...
+
+ 11+ 2006-09-29 00:00 Test1 Testing message 1
+ 12 2006-09-29 00:00 Test2 Testing message 2
+ 13 2006-09-29 00:00 Test3 Testing message 3
+ 14 2006-09-29 00:00 Test4 Testing message 4
+ 15 2006-09-29 00:00 Test5 Testing message 5
+ 16 2006-09-29 00:00 Test6 Testing message 6
+ 17 2006-09-29 00:00 Test7 Testing message 7
+ 18 2006-09-29 00:00 Test8 Testing message 8
+ 19 2006-09-29 00:00 Test9 Testing message 9
+ 20 2006-09-29 00:00 Test10 Testing message 10
+!
+
+# Test nonempty redirected stdin.
+cd "$MMH_TEST_DIR"
+f=mbox
+runandcheck "packf +inbox 1-10 >$f && inc -file - <$f" <<!
+Incorporating new mail into inbox...
+
+ 21+ 2006-09-29 00:00 Test1 Testing message 1
+ 22 2006-09-29 00:00 Test2 Testing message 2
+ 23 2006-09-29 00:00 Test3 Testing message 3
+ 24 2006-09-29 00:00 Test4 Testing message 4
+ 25 2006-09-29 00:00 Test5 Testing message 5
+ 26 2006-09-29 00:00 Test6 Testing message 6
+ 27 2006-09-29 00:00 Test7 Testing message 7
+ 28 2006-09-29 00:00 Test8 Testing message 8
+ 29 2006-09-29 00:00 Test9 Testing message 9
+ 30 2006-09-29 00:00 Test10 Testing message 10
+!
+rm "$f"
+unset f