1 files changed, 132 insertions, 0 deletions
diff --git a/url.c b/url.c
new file mode 100644
index 0000000000..7ca2a69e10
--- /dev/null
+++ b/url.c
@@ -0,0 +1,132 @@
+#include "cache.h"
+#include "url.h"
+
+int is_urlschemechar(int first_flag, int ch)
+{
+	/*
+	 * The set of valid URL schemes, as per STD66 (RFC3986) is
+	 * '[A-Za-z][A-Za-z0-9+.-]*'. But use sightly looser check
+	 * of '[A-Za-z0-9][A-Za-z0-9+.-]*' because earlier version
+	 * of check used '[A-Za-z0-9]+' so not to break any remote
+	 * helpers.
+	 */
+	int alphanumeric, special;
+	alphanumeric = ch > 0 && isalnum(ch);
+	special = ch == '+' || ch == '-' || ch == '.';
+	return alphanumeric || (!first_flag && special);
+}
+
+int is_url(const char *url)
+{
+	/* Is "scheme" part reasonable? */
+	if (!url || !is_urlschemechar(1, *url++))
+		return 0;
+	while (*url && *url != ':') {
+		if (!is_urlschemechar(0, *url++))
+			return 0;
+	}
+	/* We've seen "scheme"; we want colon-slash-slash */
+	return (url[0] == ':' && url[1] == '/' && url[2] == '/');
+}
+
+static int url_decode_char(const char *q)
+{
+	int i;
+	unsigned char val = 0;
+	for (i = 0; i < 2; i++) {
+		unsigned char c = *q++;
+		val <<= 4;
+		if (c >= '0' && c <= '9')
+			val += c - '0';
+		else if (c >= 'a' && c <= 'f')
+			val += c - 'a' + 10;
+		else if (c >= 'A' && c <= 'F')
+			val += c - 'A' + 10;
+		else
+			return -1;
+	}
+	return val;
+}
+
+static char *url_decode_internal(const char **query, int len,
+				 const char *stop_at, struct strbuf *out,
+				 int decode_plus)
+{
+	const char *q = *query;
+
+	while (len) {
+		unsigned char c = *q;
+
+		if (!c)
+			break;
+		if (stop_at && strchr(stop_at, c)) {
+			q++;
+			len--;
+			break;
+		}
+
+		if (c == '%') {
+			int val = url_decode_char(q + 1);
+			if (0 <= val) {
+				strbuf_addch(out, val);
+				q += 3;
+				len -= 3;
+				continue;
+			}
+		}
+
+		if (decode_plus && c == '+')
+			strbuf_addch(out, ' ');
+		else
+			strbuf_addch(out, c);
+		q++;
+		len--;
+	}
+	*query = q;
+	return strbuf_detach(out, NULL);
+}
+
+char *url_decode(const char *url)
+{
+	return url_decode_mem(url, strlen(url));
+}
+
+char *url_decode_mem(const char *url, int len)
+{
+	struct strbuf out = STRBUF_INIT;
+	const char *colon = memchr(url, ':', len);
+
+	/* Skip protocol part if present */
+	if (colon && url < colon) {
+		strbuf_add(&out, url, colon - url);
+		len -= colon - url;
+		url = colon;
+	}
+	return url_decode_internal(&url, len, NULL, &out, 0);
+}
+
+char *url_decode_parameter_name(const char **query)
+{
+	struct strbuf out = STRBUF_INIT;
+	return url_decode_internal(query, -1, "&=", &out, 1);
+}
+
+char *url_decode_parameter_value(const char **query)
+{
+	struct strbuf out = STRBUF_INIT;
+	return url_decode_internal(query, -1, "&", &out, 1);
+}
+
+void end_url_with_slash(struct strbuf *buf, const char *url)
+{
+	strbuf_addstr(buf, url);
+	if (buf->len && buf->buf[buf->len - 1] != '/')
+		strbuf_addch(buf, '/');
+}
+
+void str_end_url_with_slash(const char *url, char **dest) {
+	struct strbuf buf = STRBUF_INIT;
+	end_url_with_slash(&buf, url);
+	free(*dest);
+	*dest = strbuf_detach(&buf, NULL);
+}