archive --add-virtual-file: allow paths containing colons

By allowing the path to be enclosed in double-quotes, we can avoid
the limitation that paths cannot contain colons.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-archive.txt

@@ -69,10 +69,16 @@ OPTIONS
 	by concatenating the value of the last `--prefix` option (if any)
 	before this `--add-virtual-file` and `<path>`.
 +
-The `<path>` cannot contain any colon, the file mode is limited to
-a regular file, and the option may be subject to platform-dependent
-command-line limits. For non-trivial cases, write an untracked file
-and use `--add-file` instead.
+The `<path>` argument can start and end with a literal double-quote
+character; the contained file name is interpreted as a C-style string,
+i.e. the backslash is interpreted as escape character. The path must
+be quoted if it contains a colon, to avoid the colon from being
+misinterpreted as the separator between the path and the contents, or
+if the path begins or ends with a double-quote character.
++
+The file mode is limited to a regular file, and the option may be
+subject to platform-dependent command-line limits. For non-trivial
+cases, write an untracked file and use `--add-file` instead.
 
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree

archive.c

@@ -9,6 +9,7 @@
 #include "parse-options.h"
 #include "unpack-trees.h"
 #include "dir.h"
+#include "quote.h"
 
 static char const * const archive_usage[] = {
 	N_("git archive [<options>] <tree-ish> [<path>...]"),
@@ -535,22 +536,31 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 			die(_("Not a regular file: %s"), path);
 		info->content = NULL; /* read the file later */
 	} else if (!strcmp(opt->long_name, "add-virtual-file")) {
-		const char *colon = strchr(arg, ':');
-		char *p;
+		struct strbuf buf = STRBUF_INIT;
+		const char *p = arg;
+
+		if (*p != '"')
+			p = strchr(p, ':');
+		else if (unquote_c_style(&buf, p, &p) < 0)
+			die(_("unclosed quote: '%s'"), arg);
 
-		if (!colon)
+		if (!p || *p != ':')
 			die(_("missing colon: '%s'"), arg);
 
-		p = xstrndup(arg, colon - arg);
-		if (!args->prefix)
-			path = p;
-		else {
-			path = prefix_filename(args->prefix, p);
-			free(p);
+		if (p == arg)
+			die(_("empty file name: '%s'"), arg);
+
+		path = buf.len ?
+			strbuf_detach(&buf, NULL) : xstrndup(arg, p - arg);
+
+		if (args->prefix) {
+			char *save = path;
+			path = prefix_filename(args->prefix, path);
+			free(save);
 		}
 		memset(&info->stat, 0, sizeof(info->stat));
 		info->stat.st_mode = S_IFREG | 0644;
-		info->content = xstrdup(colon + 1);
+		info->content = xstrdup(p + 1);
 		info->stat.st_size = strlen(info->content);
 	} else {
 		BUG("add_file_cb() called for %s", opt->long_name);

t/t5003-archive-zip.sh

@@ -207,13 +207,21 @@ check_zip with_untracked
 check_added with_untracked untracked untracked
 
 test_expect_success UNZIP 'git archive --format=zip --add-virtual-file' '
+	if test_have_prereq FUNNYNAMES
+	then
+		PATHNAME="pathname with : colon"
+	else
+		PATHNAME="pathname without colon"
+	fi &&
 	git archive --format=zip >with_file_with_content.zip \
+		--add-virtual-file=\""$PATHNAME"\": \
 		--add-virtual-file=hello:world $EMPTY_TREE &&
 	test_when_finished "rm -rf tmp-unpack" &&
 	mkdir tmp-unpack && (
 		cd tmp-unpack &&
 		"$GIT_UNZIP" ../with_file_with_content.zip &&
 		test_path_is_file hello &&
+		test_path_is_file "$PATHNAME" &&
 		test world = $(cat hello)
 	)
 '