Second batch for 2.14
[gitweb.git] / ref-filter.c
index f38dee4f605df344315e0202487aeebc623f6582..1fc5e9970db1b821384e61942db856504ce46902 100644 (file)
 #include "tag.h"
 #include "quote.h"
 #include "ref-filter.h"
+#include "revision.h"
+#include "utf8.h"
+#include "git-compat-util.h"
+#include "version.h"
+#include "trailer.h"
+#include "wt-status.h"
+#include "commit-slab.h"
+
+static struct ref_msg {
+       const char *gone;
+       const char *ahead;
+       const char *behind;
+       const char *ahead_behind;
+} msgs = {
+        /* Untranslated plumbing messages: */
+       "gone",
+       "ahead %d",
+       "behind %d",
+       "ahead %d, behind %d"
+};
+
+void setup_ref_filter_porcelain_msg(void)
+{
+       msgs.gone = _("gone");
+       msgs.ahead = _("ahead %d");
+       msgs.behind = _("behind %d");
+       msgs.ahead_behind = _("ahead %d, behind %d");
+}
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
+typedef enum { COMPARE_EQUAL, COMPARE_UNEQUAL, COMPARE_NONE } cmp_status;
+
+struct align {
+       align_type position;
+       unsigned int width;
+};
+
+struct if_then_else {
+       cmp_status cmp_status;
+       const char *str;
+       unsigned int then_atom_seen : 1,
+               else_atom_seen : 1,
+               condition_satisfied : 1;
+};
+
+struct refname_atom {
+       enum { R_NORMAL, R_SHORT, R_LSTRIP, R_RSTRIP } option;
+       int lstrip, rstrip;
+};
+
+/*
+ * An atom is a valid field atom listed below, possibly prefixed with
+ * a "*" to denote deref_tag().
+ *
+ * We parse given format string and sort specifiers, and make a list
+ * of properties that we need to extract out of objects.  ref_array_item
+ * structure will hold an array of values extracted that can be
+ * indexed with the "atom number", which is an index into this
+ * array.
+ */
+static struct used_atom {
+       const char *name;
+       cmp_type type;
+       union {
+               char color[COLOR_MAXLEN];
+               struct align align;
+               struct {
+                       enum { RR_REF, RR_TRACK, RR_TRACKSHORT } option;
+                       struct refname_atom refname;
+                       unsigned int nobracket : 1;
+               } remote_ref;
+               struct {
+                       enum { C_BARE, C_BODY, C_BODY_DEP, C_LINES, C_SIG, C_SUB, C_TRAILERS } option;
+                       unsigned int nlines;
+               } contents;
+               struct {
+                       cmp_status cmp_status;
+                       const char *str;
+               } if_then_else;
+               struct {
+                       enum { O_FULL, O_LENGTH, O_SHORT } option;
+                       unsigned int length;
+               } objectname;
+               struct refname_atom refname;
+       } u;
+} *used_atom;
+static int used_atom_cnt, need_tagged, need_symref;
+static int need_color_reset_at_eol;
+
+static void color_atom_parser(struct used_atom *atom, const char *color_value)
+{
+       if (!color_value)
+               die(_("expected format: %%(color:<color>)"));
+       if (color_parse(color_value, atom->u.color) < 0)
+               die(_("unrecognized color: %%(color:%s)"), color_value);
+}
+
+static void refname_atom_parser_internal(struct refname_atom *atom,
+                                        const char *arg, const char *name)
+{
+       if (!arg)
+               atom->option = R_NORMAL;
+       else if (!strcmp(arg, "short"))
+               atom->option = R_SHORT;
+       else if (skip_prefix(arg, "lstrip=", &arg) ||
+                skip_prefix(arg, "strip=", &arg)) {
+               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);
+}
+
+static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
+{
+       struct string_list params = STRING_LIST_INIT_DUP;
+       int i;
+
+       if (!arg) {
+               atom->u.remote_ref.option = RR_REF;
+               refname_atom_parser_internal(&atom->u.remote_ref.refname,
+                                            arg, atom->name);
+               return;
+       }
+
+       atom->u.remote_ref.nobracket = 0;
+       string_list_split(&params, arg, ',', -1);
+
+       for (i = 0; i < params.nr; i++) {
+               const char *s = params.items[i].string;
+
+               if (!strcmp(s, "track"))
+                       atom->u.remote_ref.option = RR_TRACK;
+               else if (!strcmp(s, "trackshort"))
+                       atom->u.remote_ref.option = RR_TRACKSHORT;
+               else if (!strcmp(s, "nobracket"))
+                       atom->u.remote_ref.nobracket = 1;
+               else {
+                       atom->u.remote_ref.option = RR_REF;
+                       refname_atom_parser_internal(&atom->u.remote_ref.refname,
+                                                    arg, atom->name);
+               }
+       }
+
+       string_list_clear(&params, 0);
+}
+
+static void body_atom_parser(struct used_atom *atom, const char *arg)
+{
+       if (arg)
+               die(_("%%(body) does not take arguments"));
+       atom->u.contents.option = C_BODY_DEP;
+}
+
+static void subject_atom_parser(struct used_atom *atom, const char *arg)
+{
+       if (arg)
+               die(_("%%(subject) does not take arguments"));
+       atom->u.contents.option = C_SUB;
+}
+
+static void trailers_atom_parser(struct used_atom *atom, const char *arg)
+{
+       if (arg)
+               die(_("%%(trailers) does not take arguments"));
+       atom->u.contents.option = C_TRAILERS;
+}
+
+static void contents_atom_parser(struct used_atom *atom, const char *arg)
+{
+       if (!arg)
+               atom->u.contents.option = C_BARE;
+       else if (!strcmp(arg, "body"))
+               atom->u.contents.option = C_BODY;
+       else if (!strcmp(arg, "signature"))
+               atom->u.contents.option = C_SIG;
+       else if (!strcmp(arg, "subject"))
+               atom->u.contents.option = C_SUB;
+       else if (!strcmp(arg, "trailers"))
+               atom->u.contents.option = C_TRAILERS;
+       else if (skip_prefix(arg, "lines=", &arg)) {
+               atom->u.contents.option = C_LINES;
+               if (strtoul_ui(arg, 10, &atom->u.contents.nlines))
+                       die(_("positive value expected contents:lines=%s"), arg);
+       } else
+               die(_("unrecognized %%(contents) argument: %s"), arg);
+}
+
+static void objectname_atom_parser(struct used_atom *atom, const char *arg)
+{
+       if (!arg)
+               atom->u.objectname.option = O_FULL;
+       else if (!strcmp(arg, "short"))
+               atom->u.objectname.option = O_SHORT;
+       else if (skip_prefix(arg, "short=", &arg)) {
+               atom->u.objectname.option = O_LENGTH;
+               if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
+                   atom->u.objectname.length == 0)
+                       die(_("positive value expected objectname:short=%s"), arg);
+               if (atom->u.objectname.length < MINIMUM_ABBREV)
+                       atom->u.objectname.length = MINIMUM_ABBREV;
+       } else
+               die(_("unrecognized %%(objectname) argument: %s"), arg);
+}
+
+static void refname_atom_parser(struct used_atom *atom, const char *arg)
+{
+       return refname_atom_parser_internal(&atom->u.refname, arg, atom->name);
+}
+
+static align_type parse_align_position(const char *s)
+{
+       if (!strcmp(s, "right"))
+               return ALIGN_RIGHT;
+       else if (!strcmp(s, "middle"))
+               return ALIGN_MIDDLE;
+       else if (!strcmp(s, "left"))
+               return ALIGN_LEFT;
+       return -1;
+}
+
+static void align_atom_parser(struct used_atom *atom, const char *arg)
+{
+       struct align *align = &atom->u.align;
+       struct string_list params = STRING_LIST_INIT_DUP;
+       int i;
+       unsigned int width = ~0U;
+
+       if (!arg)
+               die(_("expected format: %%(align:<width>,<position>)"));
+
+       align->position = ALIGN_LEFT;
+
+       string_list_split(&params, arg, ',', -1);
+       for (i = 0; i < params.nr; i++) {
+               const char *s = params.items[i].string;
+               int position;
+
+               if (skip_prefix(s, "position=", &s)) {
+                       position = parse_align_position(s);
+                       if (position < 0)
+                               die(_("unrecognized position:%s"), s);
+                       align->position = position;
+               } else if (skip_prefix(s, "width=", &s)) {
+                       if (strtoul_ui(s, 10, &width))
+                               die(_("unrecognized width:%s"), s);
+               } else if (!strtoul_ui(s, 10, &width))
+                       ;
+               else if ((position = parse_align_position(s)) >= 0)
+                       align->position = position;
+               else
+                       die(_("unrecognized %%(align) argument: %s"), s);
+       }
+
+       if (width == ~0U)
+               die(_("positive width expected with the %%(align) atom"));
+       align->width = width;
+       string_list_clear(&params, 0);
+}
+
+static void if_atom_parser(struct used_atom *atom, const char *arg)
+{
+       if (!arg) {
+               atom->u.if_then_else.cmp_status = COMPARE_NONE;
+               return;
+       } else if (skip_prefix(arg, "equals=", &atom->u.if_then_else.str)) {
+               atom->u.if_then_else.cmp_status = COMPARE_EQUAL;
+       } else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
+               atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
+       } else {
+               die(_("unrecognized %%(if) argument: %s"), arg);
+       }
+}
+
 
 static struct {
        const char *name;
        cmp_type cmp_type;
+       void (*parser)(struct used_atom *atom, const char *arg);
 } valid_atom[] = {
-       { "refname" },
+       { "refname" , FIELD_STR, refname_atom_parser },
        { "objecttype" },
        { "objectsize", FIELD_ULONG },
-       { "objectname" },
+       { "objectname", FIELD_STR, objectname_atom_parser },
        { "tree" },
        { "parent" },
        { "numparent", FIELD_ULONG },
@@ -40,34 +317,43 @@ static struct {
        { "taggerdate", FIELD_TIME },
        { "creator" },
        { "creatordate", FIELD_TIME },
-       { "subject" },
-       { "body" },
-       { "contents" },
-       { "contents:subject" },
-       { "contents:body" },
-       { "contents:signature" },
-       { "upstream" },
-       { "push" },
-       { "symref" },
+       { "subject", FIELD_STR, subject_atom_parser },
+       { "body", FIELD_STR, body_atom_parser },
+       { "trailers", FIELD_STR, trailers_atom_parser },
+       { "contents", FIELD_STR, contents_atom_parser },
+       { "upstream", FIELD_STR, remote_ref_atom_parser },
+       { "push", FIELD_STR, remote_ref_atom_parser },
+       { "symref", FIELD_STR, refname_atom_parser },
        { "flag" },
        { "HEAD" },
-       { "color" },
+       { "color", FIELD_STR, color_atom_parser },
+       { "align", FIELD_STR, align_atom_parser },
+       { "end" },
+       { "if", FIELD_STR, if_atom_parser },
+       { "then" },
+       { "else" },
 };
 
-/*
- * An atom is a valid field atom listed above, possibly prefixed with
- * a "*" to denote deref_tag().
- *
- * We parse given format string and sort specifiers, and make a list
- * of properties that we need to extract out of objects.  ref_array_item
- * structure will hold an array of values extracted that can be
- * indexed with the "atom number", which is an index into this
- * array.
- */
-static const char **used_atom;
-static cmp_type *used_atom_type;
-static int used_atom_cnt, need_tagged, need_symref;
-static int need_color_reset_at_eol;
+#define REF_FORMATTING_STATE_INIT  { 0, NULL }
+
+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;
+       void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
+       uintmax_t value; /* used for sorting when not FIELD_STR */
+       struct used_atom *atom;
+};
 
 /*
  * Used to parse format string and sort specifiers
@@ -75,54 +361,269 @@ static int need_color_reset_at_eol;
 int parse_ref_filter_atom(const char *atom, const char *ep)
 {
        const char *sp;
-       int i, at;
+       const char *arg;
+       int i, at, atom_len;
 
        sp = atom;
        if (*sp == '*' && sp < ep)
                sp++; /* deref */
        if (ep <= sp)
-               die("malformed field name: %.*s", (int)(ep-atom), atom);
+               die(_("malformed field name: %.*s"), (int)(ep-atom), atom);
 
        /* Do we have the atom already used elsewhere? */
        for (i = 0; i < used_atom_cnt; i++) {
-               int len = strlen(used_atom[i]);
-               if (len == ep - atom && !memcmp(used_atom[i], atom, len))
+               int len = strlen(used_atom[i].name);
+               if (len == ep - atom && !memcmp(used_atom[i].name, atom, len))
                        return i;
        }
 
+       /*
+        * If the atom name has a colon, strip it and everything after
+        * it off - it specifies the format for this entry, and
+        * shouldn't be used for checking against the valid_atom
+        * table.
+        */
+       arg = memchr(sp, ':', ep - sp);
+       atom_len = (arg ? arg : ep) - sp;
+
        /* Is the atom a valid one? */
        for (i = 0; i < ARRAY_SIZE(valid_atom); i++) {
                int len = strlen(valid_atom[i].name);
-               /*
-                * If the atom name has a colon, strip it and everything after
-                * it off - it specifies the format for this entry, and
-                * shouldn't be used for checking against the valid_atom
-                * table.
-                */
-               const char *formatp = strchr(sp, ':');
-               if (!formatp || ep < formatp)
-                       formatp = ep;
-               if (len == formatp - sp && !memcmp(valid_atom[i].name, sp, len))
+               if (len == atom_len && !memcmp(valid_atom[i].name, sp, len))
                        break;
        }
 
        if (ARRAY_SIZE(valid_atom) <= i)
-               die("unknown field name: %.*s", (int)(ep-atom), atom);
+               die(_("unknown field name: %.*s"), (int)(ep-atom), atom);
 
        /* Add it in, including the deref prefix */
        at = used_atom_cnt;
        used_atom_cnt++;
        REALLOC_ARRAY(used_atom, used_atom_cnt);
-       REALLOC_ARRAY(used_atom_type, used_atom_cnt);
-       used_atom[at] = xmemdupz(atom, ep - atom);
-       used_atom_type[at] = valid_atom[i].cmp_type;
+       used_atom[at].name = xmemdupz(atom, ep - atom);
+       used_atom[at].type = valid_atom[i].cmp_type;
+       if (arg)
+               arg = used_atom[at].name + (arg - atom) + 1;
+       memset(&used_atom[at].u, 0, sizeof(used_atom[at].u));
+       if (valid_atom[i].parser)
+               valid_atom[i].parser(&used_atom[at], arg);
        if (*atom == '*')
                need_tagged = 1;
-       if (!strcmp(used_atom[at], "symref"))
+       if (!strcmp(valid_atom[i].name, "symref"))
                need_symref = 1;
        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 ref_formatting_stack *cur = *stack;
+       struct align *align = (struct align *)cur->at_end_data;
+       struct strbuf s = STRBUF_INIT;
+
+       strbuf_utf8_align(&s, align->position, align->width, cur->output.buf);
+       strbuf_swap(&cur->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->atom->u.align;
+}
+
+static void if_then_else_handler(struct ref_formatting_stack **stack)
+{
+       struct ref_formatting_stack *cur = *stack;
+       struct ref_formatting_stack *prev = cur->prev;
+       struct if_then_else *if_then_else = (struct if_then_else *)cur->at_end_data;
+
+       if (!if_then_else->then_atom_seen)
+               die(_("format: %%(if) atom used without a %%(then) atom"));
+
+       if (if_then_else->else_atom_seen) {
+               /*
+                * There is an %(else) atom: we need to drop one state from the
+                * stack, either the %(else) branch if the condition is satisfied, or
+                * the %(then) branch if it isn't.
+                */
+               if (if_then_else->condition_satisfied) {
+                       strbuf_reset(&cur->output);
+                       pop_stack_element(&cur);
+               } else {
+                       strbuf_swap(&cur->output, &prev->output);
+                       strbuf_reset(&cur->output);
+                       pop_stack_element(&cur);
+               }
+       } else if (!if_then_else->condition_satisfied) {
+               /*
+                * No %(else) atom: just drop the %(then) branch if the
+                * condition is not satisfied.
+                */
+               strbuf_reset(&cur->output);
+       }
+
+       *stack = cur;
+       free(if_then_else);
+}
+
+static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+       struct ref_formatting_stack *new;
+       struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
+
+       if_then_else->str = atomv->atom->u.if_then_else.str;
+       if_then_else->cmp_status = atomv->atom->u.if_then_else.cmp_status;
+
+       push_stack_element(&state->stack);
+       new = state->stack;
+       new->at_end = if_then_else_handler;
+       new->at_end_data = if_then_else;
+}
+
+static int is_empty(const char *s)
+{
+       while (*s != '\0') {
+               if (!isspace(*s))
+                       return 0;
+               s++;
+       }
+       return 1;
+}
+
+static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+       struct ref_formatting_stack *cur = state->stack;
+       struct if_then_else *if_then_else = NULL;
+
+       if (cur->at_end == if_then_else_handler)
+               if_then_else = (struct if_then_else *)cur->at_end_data;
+       if (!if_then_else)
+               die(_("format: %%(then) atom used without an %%(if) atom"));
+       if (if_then_else->then_atom_seen)
+               die(_("format: %%(then) atom used more than once"));
+       if (if_then_else->else_atom_seen)
+               die(_("format: %%(then) atom used after %%(else)"));
+       if_then_else->then_atom_seen = 1;
+       /*
+        * If the 'equals' or 'notequals' attribute is used then
+        * perform the required comparison. If not, only non-empty
+        * strings satisfy the 'if' condition.
+        */
+       if (if_then_else->cmp_status == COMPARE_EQUAL) {
+               if (!strcmp(if_then_else->str, cur->output.buf))
+                       if_then_else->condition_satisfied = 1;
+       } else if (if_then_else->cmp_status == COMPARE_UNEQUAL) {
+               if (strcmp(if_then_else->str, cur->output.buf))
+                       if_then_else->condition_satisfied = 1;
+       } else if (cur->output.len && !is_empty(cur->output.buf))
+               if_then_else->condition_satisfied = 1;
+       strbuf_reset(&cur->output);
+}
+
+static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+       struct ref_formatting_stack *prev = state->stack;
+       struct if_then_else *if_then_else = NULL;
+
+       if (prev->at_end == if_then_else_handler)
+               if_then_else = (struct if_then_else *)prev->at_end_data;
+       if (!if_then_else)
+               die(_("format: %%(else) atom used without an %%(if) atom"));
+       if (!if_then_else->then_atom_seen)
+               die(_("format: %%(else) atom used without a %%(then) atom"));
+       if (if_then_else->else_atom_seen)
+               die(_("format: %%(else) atom used more than once"));
+       if_then_else->else_atom_seen = 1;
+       push_stack_element(&state->stack);
+       state->stack->at_end_data = prev->at_end_data;
+       state->stack->at_end = prev->at_end;
+}
+
+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(&state->stack);
+
+       /*  Stack may have been popped within at_end(), hence reset the current pointer */
+       current = state->stack;
+
+       /*
+        * 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 (!current->prev->prev) {
+               quote_formatting(&s, current->output.buf, state->quote_style);
+               strbuf_swap(&current->output, &s);
+       }
+       strbuf_release(&s);
+       pop_stack_element(&state->stack);
+}
+
 /*
  * In a format string, find the next occurrence of %(atom).
  */
@@ -159,12 +660,12 @@ int verify_ref_format(const char *format)
                int at;
 
                if (!ep)
-                       return error("malformed format string %s", sp);
+                       return error(_("malformed format string %s"), sp);
                /* sp points at "%(" and ep points at the closing ")" */
                at = parse_ref_filter_atom(sp + 2, ep);
                cp = ep + 1;
 
-               if (skip_prefix(used_atom[at], "color:", &color))
+               if (skip_prefix(used_atom[at].name, "color:", &color))
                        need_color_reset_at_eol = !!strcmp(color, "reset");
        }
        return 0;
@@ -189,17 +690,20 @@ static void *get_obj(const unsigned char *sha1, struct object **obj, unsigned lo
 }
 
 static int grab_objectname(const char *name, const unsigned char *sha1,
-                           struct atom_value *v)
+                          struct atom_value *v, struct used_atom *atom)
 {
-       if (!strcmp(name, "objectname")) {
-               char *s = xmalloc(41);
-               strcpy(s, sha1_to_hex(sha1));
-               v->s = s;
-               return 1;
-       }
-       if (!strcmp(name, "objectname:short")) {
-               v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
-               return 1;
+       if (starts_with(name, "objectname")) {
+               if (atom->u.objectname.option == O_SHORT) {
+                       v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
+                       return 1;
+               } else if (atom->u.objectname.option == O_FULL) {
+                       v->s = xstrdup(sha1_to_hex(sha1));
+                       return 1;
+               } else if (atom->u.objectname.option == O_LENGTH) {
+                       v->s = xstrdup(find_unique_abbrev(sha1, atom->u.objectname.length));
+                       return 1;
+               } else
+                       die("BUG: unknown %%(objectname) option");
        }
        return 0;
 }
@@ -210,7 +714,7 @@ static void grab_common_values(struct atom_value *val, int deref, struct object
        int i;
 
        for (i = 0; i < used_atom_cnt; i++) {
-               const char *name = used_atom[i];
+               const char *name = used_atom[i].name;
                struct atom_value *v = &val[i];
                if (!!deref != (*name == '*'))
                        continue;
@@ -219,13 +723,11 @@ 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->value = sz;
+                       v->s = xstrfmt("%lu", sz);
                }
                else if (deref)
-                       grab_objectname(name, obj->sha1, v);
+                       grab_objectname(name, obj->oid.hash, v, &used_atom[i]);
        }
 }
 
@@ -236,7 +738,7 @@ static void grab_tag_values(struct atom_value *val, int deref, struct object *ob
        struct tag *tag = (struct tag *) obj;
 
        for (i = 0; i < used_atom_cnt; i++) {
-               const char *name = used_atom[i];
+               const char *name = used_atom[i].name;
                struct atom_value *v = &val[i];
                if (!!deref != (*name == '*'))
                        continue;
@@ -246,11 +748,8 @@ 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));
        }
 }
 
@@ -261,39 +760,29 @@ static void grab_commit_values(struct atom_value *val, int deref, struct object
        struct commit *commit = (struct commit *) obj;
 
        for (i = 0; i < used_atom_cnt; i++) {
-               const char *name = used_atom[i];
+               const char *name = used_atom[i].name;
                struct atom_value *v = &val[i];
                if (!!deref != (*name == '*'))
                        continue;
                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);
-                       v->ul = commit_list_count(commit->parents);
-                       sprintf(s, "%lu", v->ul);
-                       v->s = s;
+               else if (!strcmp(name, "numparent")) {
+                       v->value = commit_list_count(commit->parents);
+                       v->s = xstrfmt("%lu", (unsigned long)v->value);
                }
                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);
                }
        }
 }
@@ -360,7 +849,7 @@ static void grab_date(const char *buf, struct atom_value *v, const char *atomnam
 {
        const char *eoemail = strstr(buf, "> ");
        char *zone;
-       unsigned long timestamp;
+       timestamp_t timestamp;
        long tz;
        struct date_mode date_mode = { DATE_NORMAL };
        const char *formatp;
@@ -379,18 +868,18 @@ static void grab_date(const char *buf, struct atom_value *v, const char *atomnam
 
        if (!eoemail)
                goto bad;
-       timestamp = strtoul(eoemail + 2, &zone, 10);
-       if (timestamp == ULONG_MAX)
+       timestamp = parse_timestamp(eoemail + 2, &zone, 10);
+       if (timestamp == TIME_MAX)
                goto bad;
        tz = strtol(zone, NULL, 10);
        if ((tz == LONG_MIN || tz == LONG_MAX) && errno == ERANGE)
                goto bad;
        v->s = xstrdup(show_date(timestamp, tz, &date_mode));
-       v->ul = timestamp;
+       v->value = timestamp;
        return;
  bad:
        v->s = "";
-       v->ul = 0;
+       v->value = 0;
 }
 
 /* See grab_values */
@@ -401,7 +890,7 @@ static void grab_person(const char *who, struct atom_value *val, int deref, stru
        const char *wholine = NULL;
 
        for (i = 0; i < used_atom_cnt; i++) {
-               const char *name = used_atom[i];
+               const char *name = used_atom[i].name;
                struct atom_value *v = &val[i];
                if (!!deref != (*name == '*'))
                        continue;
@@ -439,7 +928,7 @@ static void grab_person(const char *who, struct atom_value *val, int deref, stru
        if (!wholine)
                return;
        for (i = 0; i < used_atom_cnt; i++) {
-               const char *name = used_atom[i];
+               const char *name = used_atom[i].name;
                struct atom_value *v = &val[i];
                if (!!deref != (*name == '*'))
                        continue;
@@ -497,6 +986,30 @@ 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)
 {
@@ -505,7 +1018,8 @@ static void grab_sub_body_contents(struct atom_value *val, int deref, struct obj
        unsigned long sublen = 0, bodylen = 0, nonsiglen = 0, siglen = 0;
 
        for (i = 0; i < used_atom_cnt; i++) {
-               const char *name = used_atom[i];
+               struct used_atom *atom = &used_atom[i];
+               const char *name = atom->name;
                struct atom_value *v = &val[i];
                if (!!deref != (*name == '*'))
                        continue;
@@ -513,10 +1027,8 @@ static void grab_sub_body_contents(struct atom_value *val, int deref, struct obj
                        name++;
                if (strcmp(name, "subject") &&
                    strcmp(name, "body") &&
-                   strcmp(name, "contents") &&
-                   strcmp(name, "contents:subject") &&
-                   strcmp(name, "contents:body") &&
-                   strcmp(name, "contents:signature"))
+                   strcmp(name, "trailers") &&
+                   !starts_with(name, "contents"))
                        continue;
                if (!subpos)
                        find_subpos(buf, sz,
@@ -524,17 +1036,30 @@ static void grab_sub_body_contents(struct atom_value *val, int deref, struct obj
                                    &bodypos, &bodylen, &nonsiglen,
                                    &sigpos, &siglen);
 
-               if (!strcmp(name, "subject"))
+               if (atom->u.contents.option == C_SUB)
                        v->s = copy_subject(subpos, sublen);
-               else if (!strcmp(name, "contents:subject"))
-                       v->s = copy_subject(subpos, sublen);
-               else if (!strcmp(name, "body"))
+               else if (atom->u.contents.option == C_BODY_DEP)
                        v->s = xmemdupz(bodypos, bodylen);
-               else if (!strcmp(name, "contents:body"))
+               else if (atom->u.contents.option == C_BODY)
                        v->s = xmemdupz(bodypos, nonsiglen);
-               else if (!strcmp(name, "contents:signature"))
+               else if (atom->u.contents.option == C_SIG)
                        v->s = xmemdupz(sigpos, siglen);
-               else if (!strcmp(name, "contents"))
+               else if (atom->u.contents.option == C_LINES) {
+                       struct strbuf s = STRBUF_INIT;
+                       const char *contents_end = bodylen + bodypos - siglen;
+
+                       /*  Size is the length of the message after removing the signature */
+                       append_lines(&s, subpos, contents_end - subpos, atom->u.contents.nlines);
+                       v->s = strbuf_detach(&s, NULL);
+               } else if (atom->u.contents.option == C_TRAILERS) {
+                       struct trailer_info info;
+
+                       /* Search for trailer info */
+                       trailer_info_get(&info, subpos);
+                       v->s = xmemdupz(info.trailer_start,
+                                       info.trailer_end - info.trailer_start);
+                       trailer_info_release(&info);
+               } else if (atom->u.contents.option == C_BARE)
                        v->s = xstrdup(subpos);
        }
 }
@@ -593,6 +1118,172 @@ static inline char *copy_advance(char *dst, const char *src)
        return dst;
 }
 
+static const char *lstrip_ref_components(const char *refname, int len)
+{
+       long remaining = len;
+       const char *start = 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) {
+               switch (*start++) {
+               case '\0':
+                       return "";
+               case '/':
+                       remaining--;
+                       break;
+               }
+       }
+
+       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;
+}
+
+static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
+                                   struct branch *branch, const char **s)
+{
+       int num_ours, num_theirs;
+       if (atom->u.remote_ref.option == RR_REF)
+               *s = show_ref(&atom->u.remote_ref.refname, refname);
+       else if (atom->u.remote_ref.option == RR_TRACK) {
+               if (stat_tracking_info(branch, &num_ours,
+                                      &num_theirs, NULL)) {
+                       *s = xstrdup(msgs.gone);
+               } else if (!num_ours && !num_theirs)
+                       *s = "";
+               else if (!num_ours)
+                       *s = xstrfmt(msgs.behind, num_theirs);
+               else if (!num_theirs)
+                       *s = xstrfmt(msgs.ahead, num_ours);
+               else
+                       *s = xstrfmt(msgs.ahead_behind,
+                                    num_ours, num_theirs);
+               if (!atom->u.remote_ref.nobracket && *s[0]) {
+                       const char *to_free = *s;
+                       *s = xstrfmt("[%s]", *s);
+                       free((void *)to_free);
+               }
+       } else if (atom->u.remote_ref.option == RR_TRACKSHORT) {
+               if (stat_tracking_info(branch, &num_ours,
+                                      &num_theirs, NULL))
+                       return;
+
+               if (!num_ours && !num_theirs)
+                       *s = "=";
+               else if (!num_ours)
+                       *s = "<";
+               else if (!num_theirs)
+                       *s = ">";
+               else
+                       *s = "<>";
+       } else
+               die("BUG: unhandled RR_* enum");
+}
+
+char *get_head_description(void)
+{
+       struct strbuf desc = STRBUF_INIT;
+       struct wt_status_state state;
+       memset(&state, 0, sizeof(state));
+       wt_status_get_state(&state, 1);
+       if (state.rebase_in_progress ||
+           state.rebase_interactive_in_progress)
+               strbuf_addf(&desc, _("(no branch, rebasing %s)"),
+                           state.branch);
+       else if (state.bisect_in_progress)
+               strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
+                           state.branch);
+       else if (state.detached_from) {
+               if (state.detached_at)
+                       /* TRANSLATORS: make sure this matches
+                          "HEAD detached at " in wt-status.c */
+                       strbuf_addf(&desc, _("(HEAD detached at %s)"),
+                               state.detached_from);
+               else
+                       /* TRANSLATORS: make sure this matches
+                          "HEAD detached from " in wt-status.c */
+                       strbuf_addf(&desc, _("(HEAD detached from %s)"),
+                               state.detached_from);
+       }
+       else
+               strbuf_addstr(&desc, _("(no branch)"));
+       free(state.branch);
+       free(state.onto);
+       free(state.detached_from);
+       return strbuf_detach(&desc, NULL);
+}
+
+static const char *get_symref(struct used_atom *atom, struct ref_array_item *ref)
+{
+       if (!ref->symref)
+               return "";
+       else
+               return show_ref(&atom->u.refname, ref->symref);
+}
+
+static const char *get_refname(struct used_atom *atom, struct ref_array_item *ref)
+{
+       if (ref->kind & FILTER_REFS_DETACHED_HEAD)
+               return get_head_description();
+       return show_ref(&atom->u.refname, ref->refname);
+}
+
 /*
  * Parse the object referred by ref, and grab needed value.
  */
@@ -607,31 +1298,34 @@ static void populate_value(struct ref_array_item *ref)
        ref->value = xcalloc(used_atom_cnt, sizeof(struct atom_value));
 
        if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
-               unsigned char unused1[20];
+               struct object_id unused1;
                ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
-                                            unused1, NULL);
+                                            unused1.hash, NULL);
                if (!ref->symref)
                        ref->symref = "";
        }
 
        /* Fill in specials first */
        for (i = 0; i < used_atom_cnt; i++) {
-               const char *name = used_atom[i];
+               struct used_atom *atom = &used_atom[i];
+               const char *name = used_atom[i].name;
                struct atom_value *v = &ref->value[i];
                int deref = 0;
                const char *refname;
-               const char *formatp;
                struct branch *branch = NULL;
 
+               v->handler = append_atom;
+               v->atom = atom;
+
                if (*name == '*') {
                        deref = 1;
                        name++;
                }
 
                if (starts_with(name, "refname"))
-                       refname = ref->refname;
+                       refname = get_refname(atom, ref);
                else if (starts_with(name, "symref"))
-                       refname = ref->symref ? ref->symref : "";
+                       refname = get_symref(atom, ref);
                else if (starts_with(name, "upstream")) {
                        const char *branch_name;
                        /* only local branches may have an upstream */
@@ -641,8 +1335,9 @@ static void populate_value(struct ref_array_item *ref)
                        branch = branch_get(branch_name);
 
                        refname = branch_get_upstream(branch, NULL);
-                       if (!refname)
-                               continue;
+                       if (refname)
+                               fill_remote_ref_details(atom, refname, branch, &v->s);
+                       continue;
                } else if (starts_with(name, "push")) {
                        const char *branch_name;
                        if (!skip_prefix(ref->refname, "refs/heads/",
@@ -653,12 +1348,10 @@ static void populate_value(struct ref_array_item *ref)
                        refname = branch_get_push(branch, NULL);
                        if (!refname)
                                continue;
+                       fill_remote_ref_details(atom, refname, branch, &v->s);
+                       continue;
                } else if (starts_with(name, "color:")) {
-                       char color[COLOR_MAXLEN] = "";
-
-                       if (color_parse(name + 6, color) < 0)
-                               die(_("unable to parse format"));
-                       v->s = xstrdup(color);
+                       v->s = atom->u.color;
                        continue;
                } else if (!strcmp(name, "flag")) {
                        char buf[256], *cp = buf;
@@ -673,7 +1366,7 @@ static void populate_value(struct ref_array_item *ref)
                                v->s = xstrdup(buf + 1);
                        }
                        continue;
-               } else if (!deref && grab_objectname(name, ref->objectname, v)) {
+               } else if (!deref && grab_objectname(name, ref->objectname, v, atom)) {
                        continue;
                } else if (!strcmp(name, "HEAD")) {
                        const char *head;
@@ -681,76 +1374,37 @@ static void populate_value(struct ref_array_item *ref)
 
                        head = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
                                                  sha1, NULL);
-                       if (!strcmp(ref->refname, head))
+                       if (head && !strcmp(ref->refname, head))
                                v->s = "*";
                        else
                                v->s = " ";
                        continue;
-               } else
+               } else if (starts_with(name, "align")) {
+                       v->handler = align_atom_handler;
                        continue;
+               } else if (!strcmp(name, "end")) {
+                       v->handler = end_atom_handler;
+                       continue;
+               } else if (starts_with(name, "if")) {
+                       const char *s;
 
-               formatp = strchr(name, ':');
-               if (formatp) {
-                       int num_ours, num_theirs;
-
-                       formatp++;
-                       if (!strcmp(formatp, "short"))
-                               refname = shorten_unambiguous_ref(refname,
-                                                     warn_ambiguous_refs);
-                       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))
-                                       continue;
-
-                               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);
-                               }
-                               continue;
-                       } else if (!strcmp(formatp, "trackshort") &&
-                                  (starts_with(name, "upstream") ||
-                                   starts_with(name, "push"))) {
-                               assert(branch);
-
-                               if (stat_tracking_info(branch, &num_ours,
-                                                       &num_theirs, NULL))
-                                       continue;
-
-                               if (!num_ours && !num_theirs)
-                                       v->s = "=";
-                               else if (!num_ours)
-                                       v->s = "<";
-                               else if (!num_theirs)
-                                       v->s = ">";
-                               else
-                                       v->s = "<>";
-                               continue;
-                       } else
-                               die("unknown %.*s format %s",
-                                   (int)(formatp - name), name, formatp);
-               }
+                       if (skip_prefix(name, "if:", &s))
+                               v->s = xstrdup(s);
+                       v->handler = if_atom_handler;
+                       continue;
+               } else if (!strcmp(name, "then")) {
+                       v->handler = then_atom_handler;
+                       continue;
+               } else if (!strcmp(name, "else")) {
+                       v->handler = else_atom_handler;
+                       continue;
+               } else
+                       continue;
 
                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++) {
@@ -763,10 +1417,10 @@ static void populate_value(struct ref_array_item *ref)
  need_obj:
        buf = get_obj(ref->objectname, &obj, &size, &eaten);
        if (!buf)
-               die("missing object %s for %s",
+               die(_("missing object %s for %s"),
                    sha1_to_hex(ref->objectname), ref->refname);
        if (!obj)
-               die("parse_object_buffer failed on %s for %s",
+               die(_("parse_object_buffer failed on %s for %s"),
                    sha1_to_hex(ref->objectname), ref->refname);
 
        grab_values(ref->value, 0, obj, buf, size);
@@ -784,7 +1438,7 @@ 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
@@ -794,10 +1448,10 @@ static void populate_value(struct ref_array_item *ref)
         */
        buf = get_obj(tagged, &obj, &size, &eaten);
        if (!buf)
-               die("missing object %s for %s",
+               die(_("missing object %s for %s"),
                    sha1_to_hex(tagged), ref->refname);
        if (!obj)
-               die("parse_object_buffer failed on %s for %s",
+               die(_("parse_object_buffer failed on %s for %s"),
                    sha1_to_hex(tagged), ref->refname);
        grab_values(ref->value, 1, obj, buf, size);
        if (!eaten)
@@ -817,15 +1471,174 @@ static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom
        *v = &ref->value[atom];
 }
 
+/*
+ * Unknown has to be "0" here, because that's the default value for
+ * contains_cache slab entries that have not yet been assigned.
+ */
+enum contains_result {
+       CONTAINS_UNKNOWN = 0,
+       CONTAINS_NO,
+       CONTAINS_YES
+};
+
+define_commit_slab(contains_cache, enum contains_result);
+
+struct ref_filter_cbdata {
+       struct ref_array *array;
+       struct ref_filter *filter;
+       struct contains_cache contains_cache;
+       struct contains_cache no_contains_cache;
+};
+
+/*
+ * 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,
+                                         struct contains_cache *cache)
+{
+       enum contains_result *cached = contains_cache_at(cache, candidate);
+
+       /* If we already have the answer cached, return that. */
+       if (*cached)
+               return *cached;
+
+       /* or are we it? */
+       if (in_commit_list(want, candidate)) {
+               *cached = CONTAINS_YES;
+               return CONTAINS_YES;
+       }
+
+       /* Otherwise, we don't know; prepare to recurse */
+       parse_commit_or_die(candidate);
+       return CONTAINS_UNKNOWN;
+}
+
+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_cache *cache)
+{
+       struct contains_stack contains_stack = { 0, 0, NULL };
+       enum contains_result result = contains_test(candidate, want, cache);
+
+       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) {
+                       *contains_cache_at(cache, commit) = CONTAINS_NO;
+                       contains_stack.nr--;
+               }
+               /*
+                * If we just popped the stack, parents->item has been marked,
+                * therefore contains_test will return a meaningful yes/no.
+                */
+               else switch (contains_test(parents->item, want, cache)) {
+               case CONTAINS_YES:
+                       *contains_cache_at(cache, commit) = CONTAINS_YES;
+                       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, cache);
+}
+
+static int commit_contains(struct ref_filter *filter, struct commit *commit,
+                          struct commit_list *list, struct contains_cache *cache)
+{
+       if (filter->with_commit_tag_algo)
+               return contains_tag_algo(commit, list, cache) == CONTAINS_YES;
+       return is_descendant_of(commit, list);
+}
+
+/*
+ * 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 struct ref_filter *filter, const char *refname)
+{
+       const char **patterns = filter->name_patterns;
+       unsigned flags = 0;
+
+       if (filter->ignore_case)
+               flags |= WM_CASEFOLD;
+
+       /*
+        * 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, flags, 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)
+static int match_name_as_path(const struct ref_filter *filter, const char *refname)
 {
+       const char **pattern = filter->name_patterns;
        int namelen = strlen(refname);
+       unsigned flags = WM_PATHNAME;
+
+       if (filter->ignore_case)
+               flags |= WM_CASEFOLD;
+
        for (; *pattern; pattern++) {
                const char *p = *pattern;
                int plen = strlen(p);
@@ -842,21 +1655,94 @@ 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, refname);
+       return match_pattern(filter, 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 struct object_id *match_points_at(struct oid_array *points_at,
+                                              const struct object_id *oid,
+                                              const char *refname)
+{
+       const struct object_id *tagged_oid = NULL;
+       struct object *obj;
+
+       if (oid_array_lookup(points_at, oid) >= 0)
+               return oid;
+       obj = parse_object(oid->hash);
+       if (!obj)
+               die(_("malformed object at '%s'"), refname);
+       if (obj->type == OBJ_TAG)
+               tagged_oid = &((struct tag *)obj)->tagged->oid;
+       if (tagged_oid && oid_array_lookup(points_at, tagged_oid) >= 0)
+               return tagged_oid;
+       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,
                                                 int flag)
 {
-       size_t len = strlen(refname);
-       struct ref_array_item *ref = xcalloc(1, sizeof(struct ref_array_item) + len + 1);
-       memcpy(ref->refname, refname, len);
-       ref->refname[len] = '\0';
+       struct ref_array_item *ref;
+       FLEX_ALLOC_STR(ref, refname, refname);
        hashcpy(ref->objectname, objectname);
        ref->flag = flag;
 
        return ref;
 }
 
+static int ref_kind_from_refname(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 (!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;
+}
+
+static int filter_ref_kind(struct ref_filter *filter, const char *refname)
+{
+       if (filter->kind == FILTER_REFS_BRANCHES ||
+           filter->kind == FILTER_REFS_REMOTES ||
+           filter->kind == FILTER_REFS_TAGS)
+               return filter->kind;
+       return ref_kind_from_refname(refname);
+}
+
 /*
  * A call-back given to for_each_ref().  Filter refs and keep them for
  * later object processing.
@@ -866,29 +1752,60 @@ 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);
+               warning(_("ignoring ref with broken name %s"), refname);
                return 0;
        }
 
        if (flag & REF_ISBROKEN) {
-               warning("ignoring broken ref %s", refname);
+               warning(_("ignoring broken ref %s"), refname);
                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, 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->no_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, filter->with_commit, &ref_cbdata->contains_cache))
+                       return 0;
+               /* ...or for the `--no-contains' option */
+               if (filter->no_commit &&
+                   commit_contains(filter, commit, filter->no_commit, &ref_cbdata->no_contains_cache))
+                       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 +1828,50 @@ 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
@@ -920,45 +1881,78 @@ 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;
+
+       init_contains_cache(&ref_cbdata.contains_cache);
+       init_contains_cache(&ref_cbdata.no_contains_cache);
+
+       /*  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);
+       }
+
+       clear_contains_cache(&ref_cbdata.contains_cache);
+       clear_contains_cache(&ref_cbdata.no_contains_cache);
+
+       /*  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)
 {
        struct atom_value *va, *vb;
        int cmp;
-       cmp_type cmp_type = used_atom_type[s->atom];
+       cmp_type cmp_type = used_atom[s->atom].type;
+       int (*cmp_fn)(const char *, const char *);
 
        get_ref_atom_value(a, s->atom, &va);
        get_ref_atom_value(b, s->atom, &vb);
-       switch (cmp_type) {
-       case FIELD_STR:
-               cmp = strcmp(va->s, vb->s);
-               break;
-       default:
-               if (va->ul < vb->ul)
+       cmp_fn = s->ignore_case ? strcasecmp : strcmp;
+       if (s->version)
+               cmp = versioncmp(va->s, vb->s);
+       else if (cmp_type == FIELD_STR)
+               cmp = cmp_fn(va->s, vb->s);
+       else {
+               if (va->value < vb->value)
                        cmp = -1;
-               else if (va->ul == vb->ul)
-                       cmp = 0;
+               else if (va->value == vb->value)
+                       cmp = cmp_fn(a->refname, b->refname);
                else
                        cmp = 1;
-               break;
        }
+
        return (s->reverse) ? -cmp : cmp;
 }
 
-static struct ref_sorting *ref_sorting;
-static int compare_refs(const void *a_, const void *b_)
+static int compare_refs(const void *a_, const void *b_, void *ref_sorting)
 {
        struct ref_array_item *a = *((struct ref_array_item **)a_);
        struct ref_array_item *b = *((struct ref_array_item **)b_);
@@ -974,90 +1968,52 @@ static int compare_refs(const void *a_, const void *b_)
 
 void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
 {
-       ref_sorting = sorting;
-       qsort(array->items, array->nr, sizeof(struct ref_array_item *), compare_refs);
+       QSORT_S(array->items, array->nr, compare_refs, sorting);
 }
 
-static void print_value(struct atom_value *v, int quote_style)
+static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
 {
-       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);
-       }
-}
+       struct strbuf *s = &state->stack->output;
 
-static int hex1(char ch)
-{
-       if ('0' <= ch && ch <= '9')
-               return ch - '0';
-       else if ('a' <= ch && ch <= 'f')
-               return ch - 'a' + 10;
-       else if ('A' <= ch && ch <= 'F')
-               return ch - 'A' + 10;
-       return -1;
-}
-static int hex2(const char *cp)
-{
-       if (cp[0] && cp[1])
-               return (hex1(cp[0]) << 4) | hex1(cp[1]);
-       else
-               return -1;
-}
-
-static void emit(const char *cp, const char *ep)
-{
        while (*cp && (!ep || cp < ep)) {
                if (*cp == '%') {
                        if (cp[1] == '%')
                                cp++;
                        else {
-                               int ch = hex2(cp + 1);
+                               int ch = hex2chr(cp + 1);
                                if (0 <= ch) {
-                                       putchar(ch);
+                                       strbuf_addch(s, ch);
                                        cp += 3;
                                        continue;
                                }
                        }
                }
-               putchar(*cp);
+               strbuf_addch(s, *cp);
                cp++;
        }
 }
 
-void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+void format_ref_array_item(struct ref_array_item *info, const char *format,
+                          int quote_style, struct strbuf *final_buf)
 {
        const char *cp, *sp, *ep;
+       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;
@@ -1066,11 +2022,34 @@ 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"));
+       strbuf_addbuf(final_buf, &state.stack->output);
+       pop_stack_element(&state.stack);
+}
+
+void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+{
+       struct strbuf final_buf = STRBUF_INIT;
+
+       format_ref_array_item(info, format, quote_style, &final_buf);
+       fwrite(final_buf.buf, 1, final_buf.len, stdout);
+       strbuf_release(&final_buf);
        putchar('\n');
 }
 
+void pretty_print_ref(const char *name, const unsigned char *sha1,
+               const char *format)
+{
+       struct ref_array_item *ref_item;
+       ref_item = new_ref_array_item(name, sha1, 0);
+       ref_item->kind = ref_kind_from_refname(name);
+       show_ref_array_item(ref_item, format, 0);
+       free_array_item(ref_item);
+}
+
 /*  If no sorting option is given, use refname to sort as default */
 struct ref_sorting *ref_default_sorting(void)
 {
@@ -1100,7 +2079,38 @@ 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];
+       int no_merged = starts_with(opt->long_name, "no");
+
+       if (rf->merge) {
+               if (no_merged) {
+                       return opterror(opt, "is incompatible with --merged", 0);
+               } else {
+                       return opterror(opt, "is incompatible with --no-merged", 0);
+               }
+       }
+
+       rf->merge = no_merged
+               ? 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;
+}