Add file completion to tcsh git completion.

For bash completion, the option '-o bashdefault' is used to indicate
that when no other choices are available, file completion should be
performed.  Since this option is not available in tcsh, no file
completion is ever performed.  Therefore, commands like 'git add ',
'git send-email ', etc, require the user to manually type out
the file name.  This can be quite annoying.

To improve the user experience we try to simulate file completion
directly in this script (although not perfectly).

The known issues with the file completion simulation are:
- Possible completions are shown with their directory prefix.
- Completions containing shell variables are not handled.
- Completions with ~ as the first character are not handled.

Signed-off-by: Marc Khouzam <marc.khouzam@ericsson.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.tcsh

@@ -19,6 +19,10 @@
 #       (e.g. ~/.git-completion.tcsh and ~/.git-completion.bash).
 #    2) Add the following line to your .tcshrc/.cshrc:
 #        source ~/.git-completion.tcsh
+#    3) For completion similar to bash, it is recommended to also
+#       add the following line to your .tcshrc/.cshrc:
+#        set autolist=ambiguous
+#       It will tell tcsh to list the possible completion choices.
 
 set __git_tcsh_completion_original_script = ${HOME}/.git-completion.bash
 set __git_tcsh_completion_script = ${HOME}/.git-completion.tcsh.bash
@@ -33,9 +37,8 @@ cat << EOF > ${__git_tcsh_completion_script}
 #!bash
 #
 # This script is GENERATED and will be overwritten automatically.
-# Do not modify it directly.  Instead, modify the git-completion.tcsh
-# script provided by Git core.
-#
+# Do not modify it directly.  Instead, modify git-completion.tcsh
+# and source it again.
 
 source ${__git_tcsh_completion_original_script}
 
@@ -61,8 +64,44 @@ fi
 _\${1}
 
 IFS=\$'\n'
+if [ \${#COMPREPLY[*]} -gt 0 ]; then
 	echo "\${COMPREPLY[*]}" | sort | uniq
+else
+	# No completions suggested.  In this case, we want tcsh to perform
+	# standard file completion.  However, there does not seem to be way
+	# to tell tcsh to do that.  To help the user, we try to simulate
+	# file completion directly in this script.
+	#
+	# Known issues:
+	#     - Possible completions are shown with their directory prefix.
+	#     - Completions containing shell variables are not handled.
+	#     - Completions with ~ as the first character are not handled.
+
+	# No file completion should be done unless we are completing beyond
+	# the git sub-command.  An improvement on the bash completion :)
+	if [ \${COMP_CWORD} -gt 1 ]; then
+		TO_COMPLETE="\${COMP_WORDS[\${COMP_CWORD}]}"
+
+		# We don't support ~ expansion: too tricky.
+		if [ "\${TO_COMPLETE:0:1}" != "~" ]; then
+			# Use ls so as to add the '/' at the end of directories.
+			RESULT=(\`ls -dp \${TO_COMPLETE}* 2> /dev/null\`)
+			echo \${RESULT[*]}
+
+			# If there is a single completion and it is a directory,
+			# we output it a second time to trick tcsh into not adding a space
+			# after it.
+			if [ \${#RESULT[*]} -eq 1 ] && [ "\${RESULT[0]: -1}" == "/" ]; then
+				echo \${RESULT[*]}
+			fi
+		fi
+	fi
+fi
+
 EOF
 
-complete git  'p/*/`bash ${__git_tcsh_completion_script} git "${COMMAND_LINE}"`/'
-complete gitk 'p/*/`bash ${__git_tcsh_completion_script} gitk "${COMMAND_LINE}"`/'
+# Don't need this variable anymore, so don't pollute the users environment
+unset __git_tcsh_completion_original_script
+
+complete git  'p,*,`bash ${__git_tcsh_completion_script} git "${COMMAND_LINE}"`,'
+complete gitk 'p,*,`bash ${__git_tcsh_completion_script} gitk "${COMMAND_LINE}"`,'