+static inline int needs_quote(int ch)
+{
+ switch (ch) {
+ case '/': case '-': case '.':
+ case 'A'...'Z': case 'a'...'z': case '0'...'9':
+ return 0;
+ default:
+ return 1;
+ }
+}
+
+static inline int hex(int v)
+{
+ if (v < 10) return '0' + v;
+ else return 'A' + v - 10;
+}
+
+static char *quote_ref_url(const char *base, const char *ref)
+{
+ const char *cp;
+ char *dp, *qref;
+ int len, baselen, ch;
+
+ baselen = strlen(base);
+ len = baselen + 6; /* "refs/" + NUL */
+ for (cp = ref; (ch = *cp) != 0; cp++, len++)
+ if (needs_quote(ch))
+ len += 2; /* extra two hex plus replacement % */
+ qref = xmalloc(len);
+ memcpy(qref, base, baselen);
+ memcpy(qref + baselen, "refs/", 5);
+ for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
+ if (needs_quote(ch)) {
+ *dp++ = '%';
+ *dp++ = hex((ch >> 4) & 0xF);
+ *dp++ = hex(ch & 0xF);
+ }
+ else
+ *dp++ = ch;
+ }
+ *dp = 0;
+
+ return qref;
+}
+