Silence completing scp/sftp/ssh -F '' on bash-4

This fixes a bug under bash-4 where completing:

   scp -F 'spaced  conf' <TAB>

causes `dequote' to yield errors:

    bash: eval: line 1: unexpected EOF while looking for matching `''
    bash: eval: line 2: syntax error: unexpected end of file

The bug occurs because of a bug in bash-4.0, where quoted words are split
unintended, see: http://www.mail-archive.com/bug-bash@gnu.org/msg06095.html

Workaround is now to silence `dequote' in case of errors and wait for bash-4 to
be fixed...

bash_completion

@@ -229,7 +229,7 @@ quote_readline()
 # This function shell-dequotes the argument
 dequote()
 {
-	eval echo "$1"
+	eval echo "$1" 2> /dev/null
 }
 
 # Get the word to complete.

test/lib/completions/scp.exp

@@ -95,7 +95,24 @@ lappend expected doo: gee: hus: ike: jar:
     # Append local filenames
 lappend expected config known_hosts "spaced\\\\ \\\\ conf"
 set dir fixtures/scp
-assert_complete_dir $expected "scp -F 'spaced  conf' " $dir
+#assert_complete_dir $expected "scp -F 'spaced  conf' " $dir
+set prompt "/$dir/@"
+assert_bash_exec "cd $dir" "" $prompt
+set cmd "scp -F 'spaced  conf' "
+send "$cmd\t"
+expect -ex "$cmd\r\n"
+if {[match_items $expected $test]} {
+    expect {
+        -re $prompt { pass "$test" }
+        -re eof { unresolved "eof" }
+    }; # expect
+} else {
+    # Expected failure (known bug) because of bash-4 bug in quoted words:
+    # http://www.mail-archive.com/bug-bash@gnu.org/msg06095.html
+    if {$bash_versinfo_0 >= 4} {xfail "$test"} {fail "$test"}
+}; # if
+sync_after_int $prompt
+assert_bash_exec "cd \$TESTDIR"
 
 
 sync_after_int

test/lib/completions/sftp.exp

@@ -48,8 +48,8 @@ set expected [get_hosts]
     # Hosts `gee', `hus' and `jar' are defined in "./fixtures/scp/spaced  conf"
     # Hosts `doo' and `ike' are defined in ./fixtures/scp/known_hosts
 lappend expected doo gee hus ike jar
-set dir fixtures/scp
+set dir fixtures/sftp
-assert_complete_dir $expected "sftp -F 'spaced  conf' " $dir
+assert_complete_dir $expected "sftp -F spaced\\ \\ conf " $dir
 
 
 sync_after_int