quote.c: separate quoting and relative path generation

This is in preparation of relative path support for ls-files, which
quotes a path only if the line terminator is not the NUL character.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

quote.c

@@ -295,42 +295,75 @@ void write_name_quotedpfx(const char *pfx, size_t pfxlen,
 	fputc(terminator, fp);
 }
 
-/* quote path as relative to the given prefix */
-char *quote_path_relative(const char *in, int len,
-			  struct strbuf *out, const char *prefix)
+static const char *path_relative(const char *in, int len,
+				 struct strbuf *sb, const char *prefix,
+				 int prefix_len);
+
+void write_name_quoted_relative(const char *name, size_t len,
+				const char *prefix, size_t prefix_len,
+				FILE *fp, int terminator)
 {
-	int needquote;
+	struct strbuf sb = STRBUF_INIT;
+
+	name = path_relative(name, len, &sb, prefix, prefix_len);
+	write_name_quoted(name, fp, terminator);
+
+	strbuf_release(&sb);
+}
+
+/*
+ * Give path as relative to prefix.
+ *
+ * The strbuf may or may not be used, so do not assume it contains the
+ * returned path.
+ */
+static const char *path_relative(const char *in, int len,
+				 struct strbuf *sb, const char *prefix,
+				 int prefix_len)
+{
+	int off, i;
 
 	if (len < 0)
 		len = strlen(in);
+	if (prefix && prefix_len < 0)
+		prefix_len = strlen(prefix);
+
+	off = 0;
+	i = 0;
+	while (i < prefix_len && i < len && prefix[i] == in[i]) {
+		if (prefix[i] == '/')
+			off = i + 1;
+		i++;
+	}
+	in += off;
+	len -= off;
+
+	if (i >= prefix_len)
+		return in;
 
-	/* "../" prefix itself does not need quoting, but "in" might. */
-	needquote = next_quote_pos(in, len) < len;
-	strbuf_setlen(out, 0);
-	strbuf_grow(out, len);
-
-	if (needquote)
-		strbuf_addch(out, '"');
-	if (prefix) {
-		int off = 0;
-		while (prefix[off] && off < len && prefix[off] == in[off])
-			if (prefix[off] == '/') {
-				prefix += off + 1;
-				in += off + 1;
-				len -= off + 1;
-				off = 0;
-			} else
-				off++;
-
-		for (; *prefix; prefix++)
-			if (*prefix == '/')
-				strbuf_addstr(out, "../");
+	strbuf_reset(sb);
+	strbuf_grow(sb, len);
+
+	while (i < prefix_len) {
+		if (prefix[i] == '/')
+			strbuf_addstr(sb, "../");
+		i++;
 	}
+	strbuf_add(sb, in, len);
+
+	return sb->buf;
+}
 
-	quote_c_style_counted (in, len, out, NULL, 1);
+/* quote path as relative to the given prefix */
+char *quote_path_relative(const char *in, int len,
+			  struct strbuf *out, const char *prefix)
+{
+	struct strbuf sb = STRBUF_INIT;
+	const char *rel = path_relative(in, len, &sb, prefix, -1);
+	strbuf_reset(out);
+	quote_c_style_counted(rel, strlen(rel), out, NULL, 0);
+	strbuf_release(&sb);
 
-	if (needquote)
-		strbuf_addch(out, '"');
 	if (!out->len)
 		strbuf_addstr(out, "./");
 

quote.h

@@ -54,9 +54,12 @@ extern void quote_two_c_style(struct strbuf *, const char *, const char *, int);
 extern void write_name_quoted(const char *name, FILE *, int terminator);
 extern void write_name_quotedpfx(const char *pfx, size_t pfxlen,
                                  const char *name, FILE *, int terminator);
+extern void write_name_quoted_relative(const char *name, size_t len,
+		const char *prefix, size_t prefix_len,
+		FILE *fp, int terminator);
 
 /* quote path as relative to the given prefix */
-char *quote_path_relative(const char *in, int len,
+extern char *quote_path_relative(const char *in, int len,
 			  struct strbuf *out, const char *prefix);
 
 /* quoting as a string literal for other languages */