ref-filter: add an 'rstrip=<N>' option to atoms which deal with refnames

diff --git a/ref-filter.c b/ref-filter.c
index 2840ca18e3f1c81b14bf5bc5db08d3efa913a89e..47e292bc46105544d5342a7e1ebe61b8cfdd36e8 100644 (file)
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -33,8 +33,8 @@ struct if_then_else {
 };
 
 struct refname_atom {
-       enum { R_NORMAL, R_SHORT, R_LSTRIP } option;
-       int lstrip;
+       enum { R_NORMAL, R_SHORT, R_LSTRIP, R_RSTRIP } option;
+       int lstrip, rstrip;
 };
 
 /*
@@ -95,6 +95,10 @@ static void refname_atom_parser_internal(struct refname_atom *atom,
                atom->option = R_LSTRIP;
                if (strtol_i(arg, 10, &atom->lstrip))
                        die(_("Integer value expected refname:lstrip=%s"), arg);
+       } else if (skip_prefix(arg, "rstrip=", &arg)) {
+               atom->option = R_RSTRIP;
+               if (strtol_i(arg, 10, &atom->rstrip))
+                       die(_("Integer value expected refname:rstrip=%s"), arg);
        } else
                die(_("unrecognized %%(%s) argument: %s"), name, arg);
 }
@@ -1125,12 +1129,45 @@ static const char *lstrip_ref_components(const char *refname, int len)
        return start;
 }
 
+static const char *rstrip_ref_components(const char *refname, int len)
+{
+       long remaining = len;
+       char *start = xstrdup(refname);
+
+       if (len < 0) {
+               int i;
+               const char *p = refname;
+
+               /* Find total no of '/' separated path-components */
+               for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
+                       ;
+               /*
+                * The number of components we need to strip is now
+                * the total minus the components to be left (Plus one
+                * because we count the number of '/', but the number
+                * of components is one more than the no of '/').
+                */
+               remaining = i + len + 1;
+       }
+
+       while (remaining-- > 0) {
+               char *p = strrchr(start, '/');
+               if (p == NULL)
+                       return "";
+               else
+                       p[0] = '\0';
+       }
+       return start;
+}
+
 static const char *show_ref(struct refname_atom *atom, const char *refname)
 {
        if (atom->option == R_SHORT)
                return shorten_unambiguous_ref(refname, warn_ambiguous_refs);
        else if (atom->option == R_LSTRIP)
                return lstrip_ref_components(refname, atom->lstrip);
+       else if (atom->option == R_RSTRIP)
+               return rstrip_ref_components(refname, atom->rstrip);
        else
                return refname;
 }