submodule--helper: die on config error when cloning module
[gitweb.git] / ref-filter.c
index f38dee4f605df344315e0202487aeebc623f6582..f097176ed93229fe75533e21dc60e0bbc5a4e7ef 100644 (file)
@@ -9,6 +9,10 @@
 #include "tag.h"
 #include "quote.h"
 #include "ref-filter.h"
+#include "revision.h"
+#include "utf8.h"
+#include "git-compat-util.h"
+#include "version.h"
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
 
@@ -43,15 +47,48 @@ static struct {
        { "subject" },
        { "body" },
        { "contents" },
-       { "contents:subject" },
-       { "contents:body" },
-       { "contents:signature" },
        { "upstream" },
        { "push" },
        { "symref" },
        { "flag" },
        { "HEAD" },
        { "color" },
+       { "align" },
+       { "end" },
+};
+
+#define REF_FORMATTING_STATE_INIT  { 0, NULL }
+
+struct align {
+       align_type position;
+       unsigned int width;
+};
+
+struct contents {
+       unsigned int lines;
+       struct object_id oid;
+};
+
+struct ref_formatting_stack {
+       struct ref_formatting_stack *prev;
+       struct strbuf output;
+       void (*at_end)(struct ref_formatting_stack *stack);
+       void *at_end_data;
+};
+
+struct ref_formatting_state {
+       int quote_style;
+       struct ref_formatting_stack *stack;
+};
+
+struct atom_value {
+       const char *s;
+       union {
+               struct align align;
+               struct contents contents;
+       } u;
+       void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
+       unsigned long ul; /* used for sorting when not FIELD_STR */
 };
 
 /*
@@ -123,6 +160,120 @@ int parse_ref_filter_atom(const char *atom, const char *ep)
        return at;
 }
 
+static void quote_formatting(struct strbuf *s, const char *str, int quote_style)
+{
+       switch (quote_style) {
+       case QUOTE_NONE:
+               strbuf_addstr(s, str);
+               break;
+       case QUOTE_SHELL:
+               sq_quote_buf(s, str);
+               break;
+       case QUOTE_PERL:
+               perl_quote_buf(s, str);
+               break;
+       case QUOTE_PYTHON:
+               python_quote_buf(s, str);
+               break;
+       case QUOTE_TCL:
+               tcl_quote_buf(s, str);
+               break;
+       }
+}
+
+static void append_atom(struct atom_value *v, struct ref_formatting_state *state)
+{
+       /*
+        * Quote formatting is only done when the stack has a single
+        * element. Otherwise quote formatting is done on the
+        * element's entire output strbuf when the %(end) atom is
+        * encountered.
+        */
+       if (!state->stack->prev)
+               quote_formatting(&state->stack->output, v->s, state->quote_style);
+       else
+               strbuf_addstr(&state->stack->output, v->s);
+}
+
+static void push_stack_element(struct ref_formatting_stack **stack)
+{
+       struct ref_formatting_stack *s = xcalloc(1, sizeof(struct ref_formatting_stack));
+
+       strbuf_init(&s->output, 0);
+       s->prev = *stack;
+       *stack = s;
+}
+
+static void pop_stack_element(struct ref_formatting_stack **stack)
+{
+       struct ref_formatting_stack *current = *stack;
+       struct ref_formatting_stack *prev = current->prev;
+
+       if (prev)
+               strbuf_addbuf(&prev->output, &current->output);
+       strbuf_release(&current->output);
+       free(current);
+       *stack = prev;
+}
+
+static void end_align_handler(struct ref_formatting_stack *stack)
+{
+       struct align *align = (struct align *)stack->at_end_data;
+       struct strbuf s = STRBUF_INIT;
+
+       strbuf_utf8_align(&s, align->position, align->width, stack->output.buf);
+       strbuf_swap(&stack->output, &s);
+       strbuf_release(&s);
+}
+
+static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+       struct ref_formatting_stack *new;
+
+       push_stack_element(&state->stack);
+       new = state->stack;
+       new->at_end = end_align_handler;
+       new->at_end_data = &atomv->u.align;
+}
+
+static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+       struct ref_formatting_stack *current = state->stack;
+       struct strbuf s = STRBUF_INIT;
+
+       if (!current->at_end)
+               die(_("format: %%(end) atom used without corresponding atom"));
+       current->at_end(current);
+
+       /*
+        * Perform quote formatting when the stack element is that of
+        * a supporting atom. If nested then perform quote formatting
+        * only on the topmost supporting atom.
+        */
+       if (!state->stack->prev->prev) {
+               quote_formatting(&s, current->output.buf, state->quote_style);
+               strbuf_swap(&current->output, &s);
+       }
+       strbuf_release(&s);
+       pop_stack_element(&state->stack);
+}
+
+static int match_atom_name(const char *name, const char *atom_name, const char **val)
+{
+       const char *body;
+
+       if (!skip_prefix(name, atom_name, &body))
+               return 0; /* doesn't even begin with "atom_name" */
+       if (!body[0]) {
+               *val = NULL; /* %(atom_name) and no customization */
+               return 1;
+       }
+       if (body[0] != ':')
+               return 0; /* "atom_namefoo" is not "atom_name" or "atom_name:..." */
+       *val = body + 1; /* "atom_name:val" */
+       return 1;
+}
+
 /*
  * In a format string, find the next occurrence of %(atom).
  */
@@ -192,9 +343,7 @@ static int grab_objectname(const char *name, const unsigned char *sha1,
                            struct atom_value *v)
 {
        if (!strcmp(name, "objectname")) {
-               char *s = xmalloc(41);
-               strcpy(s, sha1_to_hex(sha1));
-               v->s = s;
+               v->s = xstrdup(sha1_to_hex(sha1));
                return 1;
        }
        if (!strcmp(name, "objectname:short")) {
@@ -219,13 +368,11 @@ static void grab_common_values(struct atom_value *val, int deref, struct object
                if (!strcmp(name, "objecttype"))
                        v->s = typename(obj->type);
                else if (!strcmp(name, "objectsize")) {
-                       char *s = xmalloc(40);
-                       sprintf(s, "%lu", sz);
                        v->ul = sz;
-                       v->s = s;
+                       v->s = xstrfmt("%lu", sz);
                }
                else if (deref)
-                       grab_objectname(name, obj->sha1, v);
+                       grab_objectname(name, obj->oid.hash, v);
        }
 }
 
@@ -246,11 +393,8 @@ static void grab_tag_values(struct atom_value *val, int deref, struct object *ob
                        v->s = tag->tag;
                else if (!strcmp(name, "type") && tag->tagged)
                        v->s = typename(tag->tagged->type);
-               else if (!strcmp(name, "object") && tag->tagged) {
-                       char *s = xmalloc(41);
-                       strcpy(s, sha1_to_hex(tag->tagged->sha1));
-                       v->s = s;
-               }
+               else if (!strcmp(name, "object") && tag->tagged)
+                       v->s = xstrdup(oid_to_hex(&tag->tagged->oid));
        }
 }
 
@@ -268,32 +412,22 @@ static void grab_commit_values(struct atom_value *val, int deref, struct object
                if (deref)
                        name++;
                if (!strcmp(name, "tree")) {
-                       char *s = xmalloc(41);
-                       strcpy(s, sha1_to_hex(commit->tree->object.sha1));
-                       v->s = s;
+                       v->s = xstrdup(oid_to_hex(&commit->tree->object.oid));
                }
-               if (!strcmp(name, "numparent")) {
-                       char *s = xmalloc(40);
+               else if (!strcmp(name, "numparent")) {
                        v->ul = commit_list_count(commit->parents);
-                       sprintf(s, "%lu", v->ul);
-                       v->s = s;
+                       v->s = xstrfmt("%lu", v->ul);
                }
                else if (!strcmp(name, "parent")) {
-                       int num = commit_list_count(commit->parents);
-                       int i;
                        struct commit_list *parents;
-                       char *s = xmalloc(41 * num + 1);
-                       v->s = s;
-                       for (i = 0, parents = commit->parents;
-                            parents;
-                            parents = parents->next, i = i + 41) {
+                       struct strbuf s = STRBUF_INIT;
+                       for (parents = commit->parents; parents; parents = parents->next) {
                                struct commit *parent = parents->item;
-                               strcpy(s+i, sha1_to_hex(parent->object.sha1));
-                               if (parents->next)
-                                       s[i+40] = ' ';
+                               if (parents != commit->parents)
+                                       strbuf_addch(&s, ' ');
+                               strbuf_addstr(&s, oid_to_hex(&parent->object.oid));
                        }
-                       if (!i)
-                               *s = '\0';
+                       v->s = strbuf_detach(&s, NULL);
                }
        }
 }
@@ -497,6 +631,30 @@ static void find_subpos(const char *buf, unsigned long sz,
        *nonsiglen = *sig - buf;
 }
 
+/*
+ * If 'lines' is greater than 0, append that many lines from the given
+ * 'buf' of length 'size' to the given strbuf.
+ */
+static void append_lines(struct strbuf *out, const char *buf, unsigned long size, int lines)
+{
+       int i;
+       const char *sp, *eol;
+       size_t len;
+
+       sp = buf;
+
+       for (i = 0; i < lines && sp < buf + size; i++) {
+               if (i)
+                       strbuf_addstr(out, "\n    ");
+               eol = memchr(sp, '\n', size - (sp - buf));
+               len = eol ? eol - sp : size - (sp - buf);
+               strbuf_add(out, sp, len);
+               if (!eol)
+                       break;
+               sp = eol + 1;
+       }
+}
+
 /* See grab_values */
 static void grab_sub_body_contents(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
 {
@@ -507,6 +665,7 @@ static void grab_sub_body_contents(struct atom_value *val, int deref, struct obj
        for (i = 0; i < used_atom_cnt; i++) {
                const char *name = used_atom[i];
                struct atom_value *v = &val[i];
+               const char *valp = NULL;
                if (!!deref != (*name == '*'))
                        continue;
                if (deref)
@@ -516,7 +675,8 @@ static void grab_sub_body_contents(struct atom_value *val, int deref, struct obj
                    strcmp(name, "contents") &&
                    strcmp(name, "contents:subject") &&
                    strcmp(name, "contents:body") &&
-                   strcmp(name, "contents:signature"))
+                   strcmp(name, "contents:signature") &&
+                   !starts_with(name, "contents:lines="))
                        continue;
                if (!subpos)
                        find_subpos(buf, sz,
@@ -536,6 +696,16 @@ static void grab_sub_body_contents(struct atom_value *val, int deref, struct obj
                        v->s = xmemdupz(sigpos, siglen);
                else if (!strcmp(name, "contents"))
                        v->s = xstrdup(subpos);
+               else if (skip_prefix(name, "contents:lines=", &valp)) {
+                       struct strbuf s = STRBUF_INIT;
+                       const char *contents_end = bodylen + bodypos - siglen;
+
+                       if (strtoul_ui(valp, 10, &v->u.contents.lines))
+                               die(_("positive value expected contents:lines=%s"), valp);
+                       /*  Size is the length of the message after removing the signature */
+                       append_lines(&s, subpos, contents_end - subpos, v->u.contents.lines);
+                       v->s = strbuf_detach(&s, NULL);
+               }
        }
 }
 
@@ -593,6 +763,29 @@ static inline char *copy_advance(char *dst, const char *src)
        return dst;
 }
 
+static const char *strip_ref_components(const char *refname, const char *nr_arg)
+{
+       char *end;
+       long nr = strtol(nr_arg, &end, 10);
+       long remaining = nr;
+       const char *start = refname;
+
+       if (nr < 1 || *end != '\0')
+               die(":strip= requires a positive integer argument");
+
+       while (remaining) {
+               switch (*start++) {
+               case '\0':
+                       die("ref '%s' does not have %ld components to :strip",
+                           refname, nr);
+               case '/':
+                       remaining--;
+                       break;
+               }
+       }
+       return start;
+}
+
 /*
  * Parse the object referred by ref, and grab needed value.
  */
@@ -621,8 +814,11 @@ static void populate_value(struct ref_array_item *ref)
                int deref = 0;
                const char *refname;
                const char *formatp;
+               const char *valp;
                struct branch *branch = NULL;
 
+               v->handler = append_atom;
+
                if (*name == '*') {
                        deref = 1;
                        name++;
@@ -653,10 +849,12 @@ static void populate_value(struct ref_array_item *ref)
                        refname = branch_get_push(branch, NULL);
                        if (!refname)
                                continue;
-               } else if (starts_with(name, "color:")) {
+               } else if (match_atom_name(name, "color", &valp)) {
                        char color[COLOR_MAXLEN] = "";
 
-                       if (color_parse(name + 6, color) < 0)
+                       if (!valp)
+                               die(_("expected format: %%(color:<color>)"));
+                       if (color_parse(valp, color) < 0)
                                die(_("unable to parse format"));
                        v->s = xstrdup(color);
                        continue;
@@ -686,21 +884,65 @@ static void populate_value(struct ref_array_item *ref)
                        else
                                v->s = " ";
                        continue;
+               } else if (match_atom_name(name, "align", &valp)) {
+                       struct align *align = &v->u.align;
+                       struct strbuf **s, **to_free;
+                       int width = -1;
+
+                       if (!valp)
+                               die(_("expected format: %%(align:<width>,<position>)"));
+
+                       /*
+                        * TODO: Implement a function similar to strbuf_split_str()
+                        * which would omit the separator from the end of each value.
+                        */
+                       s = to_free = strbuf_split_str(valp, ',', 0);
+
+                       align->position = ALIGN_LEFT;
+
+                       while (*s) {
+                               /*  Strip trailing comma */
+                               if (s[1])
+                                       strbuf_setlen(s[0], s[0]->len - 1);
+                               if (!strtoul_ui(s[0]->buf, 10, (unsigned int *)&width))
+                                       ;
+                               else if (!strcmp(s[0]->buf, "left"))
+                                       align->position = ALIGN_LEFT;
+                               else if (!strcmp(s[0]->buf, "right"))
+                                       align->position = ALIGN_RIGHT;
+                               else if (!strcmp(s[0]->buf, "middle"))
+                                       align->position = ALIGN_MIDDLE;
+                               else
+                                       die(_("improper format entered align:%s"), s[0]->buf);
+                               s++;
+                       }
+
+                       if (width < 0)
+                               die(_("positive width expected with the %%(align) atom"));
+                       align->width = width;
+                       strbuf_list_free(to_free);
+                       v->handler = align_atom_handler;
+                       continue;
+               } else if (!strcmp(name, "end")) {
+                       v->handler = end_atom_handler;
+                       continue;
                } else
                        continue;
 
                formatp = strchr(name, ':');
                if (formatp) {
                        int num_ours, num_theirs;
+                       const char *arg;
 
                        formatp++;
                        if (!strcmp(formatp, "short"))
                                refname = shorten_unambiguous_ref(refname,
                                                      warn_ambiguous_refs);
+                       else if (skip_prefix(formatp, "strip=", &arg))
+                               refname = strip_ref_components(refname, arg);
                        else if (!strcmp(formatp, "track") &&
                                 (starts_with(name, "upstream") ||
                                  starts_with(name, "push"))) {
-                               char buf[40];
 
                                if (stat_tracking_info(branch, &num_ours,
                                                       &num_theirs, NULL))
@@ -708,17 +950,13 @@ static void populate_value(struct ref_array_item *ref)
 
                                if (!num_ours && !num_theirs)
                                        v->s = "";
-                               else if (!num_ours) {
-                                       sprintf(buf, "[behind %d]", num_theirs);
-                                       v->s = xstrdup(buf);
-                               } else if (!num_theirs) {
-                                       sprintf(buf, "[ahead %d]", num_ours);
-                                       v->s = xstrdup(buf);
-                               } else {
-                                       sprintf(buf, "[ahead %d, behind %d]",
-                                               num_ours, num_theirs);
-                                       v->s = xstrdup(buf);
-                               }
+                               else if (!num_ours)
+                                       v->s = xstrfmt("[behind %d]", num_theirs);
+                               else if (!num_theirs)
+                                       v->s = xstrfmt("[ahead %d]", num_ours);
+                               else
+                                       v->s = xstrfmt("[ahead %d, behind %d]",
+                                                      num_ours, num_theirs);
                                continue;
                        } else if (!strcmp(formatp, "trackshort") &&
                                   (starts_with(name, "upstream") ||
@@ -745,12 +983,8 @@ static void populate_value(struct ref_array_item *ref)
 
                if (!deref)
                        v->s = refname;
-               else {
-                       int len = strlen(refname);
-                       char *s = xmalloc(len + 4);
-                       sprintf(s, "%s^{}", refname);
-                       v->s = s;
-               }
+               else
+                       v->s = xstrfmt("%s^{}", refname);
        }
 
        for (i = 0; i < used_atom_cnt; i++) {
@@ -784,7 +1018,7 @@ static void populate_value(struct ref_array_item *ref)
         * If it is a tag object, see if we use a value that derefs
         * the object, and if we do grab the object it refers to.
         */
-       tagged = ((struct tag *)obj)->tagged->sha1;
+       tagged = ((struct tag *)obj)->tagged->oid.hash;
 
        /*
         * NEEDSWORK: This derefs tag only once, which
@@ -817,11 +1051,143 @@ static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom
        *v = &ref->value[atom];
 }
 
+enum contains_result {
+       CONTAINS_UNKNOWN = -1,
+       CONTAINS_NO = 0,
+       CONTAINS_YES = 1
+};
+
+/*
+ * Mimicking the real stack, this stack lives on the heap, avoiding stack
+ * overflows.
+ *
+ * At each recursion step, the stack items points to the commits whose
+ * ancestors are to be inspected.
+ */
+struct contains_stack {
+       int nr, alloc;
+       struct contains_stack_entry {
+               struct commit *commit;
+               struct commit_list *parents;
+       } *contains_stack;
+};
+
+static int in_commit_list(const struct commit_list *want, struct commit *c)
+{
+       for (; want; want = want->next)
+               if (!oidcmp(&want->item->object.oid, &c->object.oid))
+                       return 1;
+       return 0;
+}
+
+/*
+ * Test whether the candidate or one of its parents is contained in the list.
+ * Do not recurse to find out, though, but return -1 if inconclusive.
+ */
+static enum contains_result contains_test(struct commit *candidate,
+                           const struct commit_list *want)
+{
+       /* was it previously marked as containing a want commit? */
+       if (candidate->object.flags & TMP_MARK)
+               return 1;
+       /* or marked as not possibly containing a want commit? */
+       if (candidate->object.flags & UNINTERESTING)
+               return 0;
+       /* or are we it? */
+       if (in_commit_list(want, candidate)) {
+               candidate->object.flags |= TMP_MARK;
+               return 1;
+       }
+
+       if (parse_commit(candidate) < 0)
+               return 0;
+
+       return -1;
+}
+
+static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
+{
+       ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc);
+       contains_stack->contains_stack[contains_stack->nr].commit = candidate;
+       contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents;
+}
+
+static enum contains_result contains_tag_algo(struct commit *candidate,
+               const struct commit_list *want)
+{
+       struct contains_stack contains_stack = { 0, 0, NULL };
+       int result = contains_test(candidate, want);
+
+       if (result != CONTAINS_UNKNOWN)
+               return result;
+
+       push_to_contains_stack(candidate, &contains_stack);
+       while (contains_stack.nr) {
+               struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1];
+               struct commit *commit = entry->commit;
+               struct commit_list *parents = entry->parents;
+
+               if (!parents) {
+                       commit->object.flags |= UNINTERESTING;
+                       contains_stack.nr--;
+               }
+               /*
+                * If we just popped the stack, parents->item has been marked,
+                * therefore contains_test will return a meaningful 0 or 1.
+                */
+               else switch (contains_test(parents->item, want)) {
+               case CONTAINS_YES:
+                       commit->object.flags |= TMP_MARK;
+                       contains_stack.nr--;
+                       break;
+               case CONTAINS_NO:
+                       entry->parents = parents->next;
+                       break;
+               case CONTAINS_UNKNOWN:
+                       push_to_contains_stack(parents->item, &contains_stack);
+                       break;
+               }
+       }
+       free(contains_stack.contains_stack);
+       return contains_test(candidate, want);
+}
+
+static int commit_contains(struct ref_filter *filter, struct commit *commit)
+{
+       if (filter->with_commit_tag_algo)
+               return contains_tag_algo(commit, filter->with_commit);
+       return is_descendant_of(commit, filter->with_commit);
+}
+
+/*
+ * Return 1 if the refname matches one of the patterns, otherwise 0.
+ * A pattern can be a literal prefix (e.g. a refname "refs/heads/master"
+ * matches a pattern "refs/heads/mas") or a wildcard (e.g. the same ref
+ * matches "refs/heads/mas*", too).
+ */
+static int match_pattern(const char **patterns, const char *refname)
+{
+       /*
+        * When no '--format' option is given we need to skip the prefix
+        * for matching refs of tags and branches.
+        */
+       (void)(skip_prefix(refname, "refs/tags/", &refname) ||
+              skip_prefix(refname, "refs/heads/", &refname) ||
+              skip_prefix(refname, "refs/remotes/", &refname) ||
+              skip_prefix(refname, "refs/", &refname));
+
+       for (; *patterns; patterns++) {
+               if (!wildmatch(*patterns, refname, 0, NULL))
+                       return 1;
+       }
+       return 0;
+}
+
 /*
  * Return 1 if the refname matches one of the patterns, otherwise 0.
  * A pattern can be path prefix (e.g. a refname "refs/heads/master"
- * matches a pattern "refs/heads/") or a wildcard (e.g. the same ref
- * matches "refs/heads/m*",too).
+ * matches a pattern "refs/heads/" but not "refs/heads/m") or a
+ * wildcard (e.g. the same ref matches "refs/heads/m*", too).
  */
 static int match_name_as_path(const char **pattern, const char *refname)
 {
@@ -842,6 +1208,48 @@ static int match_name_as_path(const char **pattern, const char *refname)
        return 0;
 }
 
+/* Return 1 if the refname matches one of the patterns, otherwise 0. */
+static int filter_pattern_match(struct ref_filter *filter, const char *refname)
+{
+       if (!*filter->name_patterns)
+               return 1; /* No pattern always matches */
+       if (filter->match_as_path)
+               return match_name_as_path(filter->name_patterns, refname);
+       return match_pattern(filter->name_patterns, refname);
+}
+
+/*
+ * Given a ref (sha1, refname), check if the ref belongs to the array
+ * of sha1s. If the given ref is a tag, check if the given tag points
+ * at one of the sha1s in the given sha1 array.
+ * the given sha1_array.
+ * NEEDSWORK:
+ * 1. Only a single level of inderection is obtained, we might want to
+ * change this to account for multiple levels (e.g. annotated tags
+ * pointing to annotated tags pointing to a commit.)
+ * 2. As the refs are cached we might know what refname peels to without
+ * the need to parse the object via parse_object(). peel_ref() might be a
+ * more efficient alternative to obtain the pointee.
+ */
+static const unsigned char *match_points_at(struct sha1_array *points_at,
+                                           const unsigned char *sha1,
+                                           const char *refname)
+{
+       const unsigned char *tagged_sha1 = NULL;
+       struct object *obj;
+
+       if (sha1_array_lookup(points_at, sha1) >= 0)
+               return sha1;
+       obj = parse_object(sha1);
+       if (!obj)
+               die(_("malformed object at '%s'"), refname);
+       if (obj->type == OBJ_TAG)
+               tagged_sha1 = ((struct tag *)obj)->tagged->oid.hash;
+       if (tagged_sha1 && sha1_array_lookup(points_at, tagged_sha1) >= 0)
+               return tagged_sha1;
+       return NULL;
+}
+
 /* Allocate space for a new ref_array_item and copy the objectname and flag to it */
 static struct ref_array_item *new_ref_array_item(const char *refname,
                                                 const unsigned char *objectname,
@@ -857,6 +1265,34 @@ static struct ref_array_item *new_ref_array_item(const char *refname,
        return ref;
 }
 
+static int filter_ref_kind(struct ref_filter *filter, const char *refname)
+{
+       unsigned int i;
+
+       static struct {
+               const char *prefix;
+               unsigned int kind;
+       } ref_kind[] = {
+               { "refs/heads/" , FILTER_REFS_BRANCHES },
+               { "refs/remotes/" , FILTER_REFS_REMOTES },
+               { "refs/tags/", FILTER_REFS_TAGS}
+       };
+
+       if (filter->kind == FILTER_REFS_BRANCHES ||
+           filter->kind == FILTER_REFS_REMOTES ||
+           filter->kind == FILTER_REFS_TAGS)
+               return filter->kind;
+       else if (!strcmp(refname, "HEAD"))
+               return FILTER_REFS_DETACHED_HEAD;
+
+       for (i = 0; i < ARRAY_SIZE(ref_kind); i++) {
+               if (starts_with(refname, ref_kind[i].prefix))
+                       return ref_kind[i].kind;
+       }
+
+       return FILTER_REFS_OTHERS;
+}
+
 /*
  * A call-back given to for_each_ref().  Filter refs and keep them for
  * later object processing.
@@ -866,6 +1302,8 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid,
        struct ref_filter_cbdata *ref_cbdata = cb_data;
        struct ref_filter *filter = ref_cbdata->filter;
        struct ref_array_item *ref;
+       struct commit *commit = NULL;
+       unsigned int kind;
 
        if (flag & REF_BAD_NAME) {
                warning("ignoring ref with broken name %s", refname);
@@ -877,18 +1315,43 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid,
                return 0;
        }
 
-       if (*filter->name_patterns && !match_name_as_path(filter->name_patterns, refname))
+       /* Obtain the current ref kind from filter_ref_kind() and ignore unwanted refs. */
+       kind = filter_ref_kind(filter, refname);
+       if (!(kind & filter->kind))
+               return 0;
+
+       if (!filter_pattern_match(filter, refname))
                return 0;
 
+       if (filter->points_at.nr && !match_points_at(&filter->points_at, oid->hash, refname))
+               return 0;
+
+       /*
+        * A merge filter is applied on refs pointing to commits. Hence
+        * obtain the commit using the 'oid' available and discard all
+        * non-commits early. The actual filtering is done later.
+        */
+       if (filter->merge_commit || filter->with_commit || filter->verbose) {
+               commit = lookup_commit_reference_gently(oid->hash, 1);
+               if (!commit)
+                       return 0;
+               /* We perform the filtering for the '--contains' option */
+               if (filter->with_commit &&
+                   !commit_contains(filter, commit))
+                       return 0;
+       }
+
        /*
         * We do not open the object yet; sort may only need refname
         * to do its job and the resulting list may yet to be pruned
         * by maxcount logic.
         */
        ref = new_ref_array_item(refname, oid->hash, flag);
+       ref->commit = commit;
 
        REALLOC_ARRAY(ref_cbdata->array->items, ref_cbdata->array->nr + 1);
        ref_cbdata->array->items[ref_cbdata->array->nr++] = ref;
+       ref->kind = kind;
        return 0;
 }
 
@@ -911,6 +1374,50 @@ void ref_array_clear(struct ref_array *array)
        array->nr = array->alloc = 0;
 }
 
+static void do_merge_filter(struct ref_filter_cbdata *ref_cbdata)
+{
+       struct rev_info revs;
+       int i, old_nr;
+       struct ref_filter *filter = ref_cbdata->filter;
+       struct ref_array *array = ref_cbdata->array;
+       struct commit **to_clear = xcalloc(sizeof(struct commit *), array->nr);
+
+       init_revisions(&revs, NULL);
+
+       for (i = 0; i < array->nr; i++) {
+               struct ref_array_item *item = array->items[i];
+               add_pending_object(&revs, &item->commit->object, item->refname);
+               to_clear[i] = item->commit;
+       }
+
+       filter->merge_commit->object.flags |= UNINTERESTING;
+       add_pending_object(&revs, &filter->merge_commit->object, "");
+
+       revs.limited = 1;
+       if (prepare_revision_walk(&revs))
+               die(_("revision walk setup failed"));
+
+       old_nr = array->nr;
+       array->nr = 0;
+
+       for (i = 0; i < old_nr; i++) {
+               struct ref_array_item *item = array->items[i];
+               struct commit *commit = item->commit;
+
+               int is_merged = !!(commit->object.flags & UNINTERESTING);
+
+               if (is_merged == (filter->merge == REF_FILTER_MERGED_INCLUDE))
+                       array->items[array->nr++] = array->items[i];
+               else
+                       free_array_item(item);
+       }
+
+       for (i = 0; i < old_nr; i++)
+               clear_commit_marks(to_clear[i], ALL_REV_FLAGS);
+       clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
+       free(to_clear);
+}
+
 /*
  * API for filtering a set of refs. Based on the type of refs the user
  * has requested, we iterate through those refs and apply filters
@@ -920,17 +1427,44 @@ void ref_array_clear(struct ref_array *array)
 int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int type)
 {
        struct ref_filter_cbdata ref_cbdata;
+       int ret = 0;
+       unsigned int broken = 0;
 
        ref_cbdata.array = array;
        ref_cbdata.filter = filter;
 
-       if (type & (FILTER_REFS_ALL | FILTER_REFS_INCLUDE_BROKEN))
-               return for_each_rawref(ref_filter_handler, &ref_cbdata);
-       else if (type & FILTER_REFS_ALL)
-               return for_each_ref(ref_filter_handler, &ref_cbdata);
-       else
+       if (type & FILTER_REFS_INCLUDE_BROKEN)
+               broken = 1;
+       filter->kind = type & FILTER_REFS_KIND_MASK;
+
+       /*  Simple per-ref filtering */
+       if (!filter->kind)
                die("filter_refs: invalid type");
-       return 0;
+       else {
+               /*
+                * For common cases where we need only branches or remotes or tags,
+                * we only iterate through those refs. If a mix of refs is needed,
+                * we iterate over all refs and filter out required refs with the help
+                * of filter_ref_kind().
+                */
+               if (filter->kind == FILTER_REFS_BRANCHES)
+                       ret = for_each_fullref_in("refs/heads/", ref_filter_handler, &ref_cbdata, broken);
+               else if (filter->kind == FILTER_REFS_REMOTES)
+                       ret = for_each_fullref_in("refs/remotes/", ref_filter_handler, &ref_cbdata, broken);
+               else if (filter->kind == FILTER_REFS_TAGS)
+                       ret = for_each_fullref_in("refs/tags/", ref_filter_handler, &ref_cbdata, broken);
+               else if (filter->kind & FILTER_REFS_ALL)
+                       ret = for_each_fullref_in("", ref_filter_handler, &ref_cbdata, broken);
+               if (!ret && (filter->kind & FILTER_REFS_DETACHED_HEAD))
+                       head_ref(ref_filter_handler, &ref_cbdata);
+       }
+
+
+       /*  Filters that need revision walking */
+       if (filter->merge_commit)
+               do_merge_filter(&ref_cbdata);
+
+       return ret;
 }
 
 static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, struct ref_array_item *b)
@@ -941,19 +1475,19 @@ static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, stru
 
        get_ref_atom_value(a, s->atom, &va);
        get_ref_atom_value(b, s->atom, &vb);
-       switch (cmp_type) {
-       case FIELD_STR:
+       if (s->version)
+               cmp = versioncmp(va->s, vb->s);
+       else if (cmp_type == FIELD_STR)
                cmp = strcmp(va->s, vb->s);
-               break;
-       default:
+       else {
                if (va->ul < vb->ul)
                        cmp = -1;
                else if (va->ul == vb->ul)
-                       cmp = 0;
+                       cmp = strcmp(a->refname, b->refname);
                else
                        cmp = 1;
-               break;
        }
+
        return (s->reverse) ? -cmp : cmp;
 }
 
@@ -978,32 +1512,6 @@ void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
        qsort(array->items, array->nr, sizeof(struct ref_array_item *), compare_refs);
 }
 
-static void print_value(struct atom_value *v, int quote_style)
-{
-       struct strbuf sb = STRBUF_INIT;
-       switch (quote_style) {
-       case QUOTE_NONE:
-               fputs(v->s, stdout);
-               break;
-       case QUOTE_SHELL:
-               sq_quote_buf(&sb, v->s);
-               break;
-       case QUOTE_PERL:
-               perl_quote_buf(&sb, v->s);
-               break;
-       case QUOTE_PYTHON:
-               python_quote_buf(&sb, v->s);
-               break;
-       case QUOTE_TCL:
-               tcl_quote_buf(&sb, v->s);
-               break;
-       }
-       if (quote_style != QUOTE_NONE) {
-               fputs(sb.buf, stdout);
-               strbuf_release(&sb);
-       }
-}
-
 static int hex1(char ch)
 {
        if ('0' <= ch && ch <= '9')
@@ -1022,8 +1530,10 @@ static int hex2(const char *cp)
                return -1;
 }
 
-static void emit(const char *cp, const char *ep)
+static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
 {
+       struct strbuf *s = &state->stack->output;
+
        while (*cp && (!ep || cp < ep)) {
                if (*cp == '%') {
                        if (cp[1] == '%')
@@ -1031,13 +1541,13 @@ static void emit(const char *cp, const char *ep)
                        else {
                                int ch = hex2(cp + 1);
                                if (0 <= ch) {
-                                       putchar(ch);
+                                       strbuf_addch(s, ch);
                                        cp += 3;
                                        continue;
                                }
                        }
                }
-               putchar(*cp);
+               strbuf_addch(s, *cp);
                cp++;
        }
 }
@@ -1045,19 +1555,24 @@ static void emit(const char *cp, const char *ep)
 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
 {
        const char *cp, *sp, *ep;
+       struct strbuf *final_buf;
+       struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
+
+       state.quote_style = quote_style;
+       push_stack_element(&state.stack);
 
        for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
                struct atom_value *atomv;
 
                ep = strchr(sp, ')');
                if (cp < sp)
-                       emit(cp, sp);
+                       append_literal(cp, sp, &state);
                get_ref_atom_value(info, parse_ref_filter_atom(sp + 2, ep), &atomv);
-               print_value(atomv, quote_style);
+               atomv->handler(atomv, &state);
        }
        if (*cp) {
                sp = cp + strlen(cp);
-               emit(cp, sp);
+               append_literal(cp, sp, &state);
        }
        if (need_color_reset_at_eol) {
                struct atom_value resetv;
@@ -1066,8 +1581,13 @@ void show_ref_array_item(struct ref_array_item *info, const char *format, int qu
                if (color_parse("reset", color) < 0)
                        die("BUG: couldn't parse 'reset' as a color");
                resetv.s = color;
-               print_value(&resetv, quote_style);
+               append_atom(&resetv, &state);
        }
+       if (state.stack->prev)
+               die(_("format: %%(end) atom missing"));
+       final_buf = &state.stack->output;
+       fwrite(final_buf->buf, 1, final_buf->len, stdout);
+       pop_stack_element(&state.stack);
        putchar('\n');
 }
 
@@ -1100,7 +1620,29 @@ int parse_opt_ref_sorting(const struct option *opt, const char *arg, int unset)
                s->reverse = 1;
                arg++;
        }
+       if (skip_prefix(arg, "version:", &arg) ||
+           skip_prefix(arg, "v:", &arg))
+               s->version = 1;
        len = strlen(arg);
        s->atom = parse_ref_filter_atom(arg, arg+len);
        return 0;
 }
+
+int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset)
+{
+       struct ref_filter *rf = opt->value;
+       unsigned char sha1[20];
+
+       rf->merge = starts_with(opt->long_name, "no")
+               ? REF_FILTER_MERGED_OMIT
+               : REF_FILTER_MERGED_INCLUDE;
+
+       if (get_sha1(arg, sha1))
+               die(_("malformed object name %s"), arg);
+
+       rf->merge_commit = lookup_commit_reference_gently(sha1, 0);
+       if (!rf->merge_commit)
+               return opterror(opt, "must point to a commit", 0);
+
+       return 0;
+}