ref-filter: implement %(if), %(then), and %(else) atoms
Implement %(if), %(then) and %(else) atoms. Used as %(if)...%(then)...%(end) or %(if)...%(then)...%(else)...%(end). If the format string between %(if) and %(then) expands to an empty string, or to only whitespaces, then the whole %(if)...%(end) expands to the string following %(then). Otherwise, it expands to the string following %(else), if any. Nesting of this construct is possible. This is in preparation for porting over `git branch -l` to use ref-filter APIs for printing. Add documentation and tests regarding the same. Mentored-by: Christian Couder <christian.couder@gmail.com> Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr> Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Karthik Nayak committed
Jan 10, 2017 at 14:19 UTC
c58492d4347fb6ee68fbb59b40e34ffde4dc2389
3 files changed
+237
-7
Documentation/git-for-each-ref.txt
+34
@@ -149,6 +149,16 @@ align::
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quoted, but if nested then only the topmost level performs
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quoting.
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+if::
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+ Used as %(if)...%(then)...%(end) or
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+ %(if)...%(then)...%(else)...%(end). If there is an atom with
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+ value or string literal after the %(if) then everything after
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+ the %(then) is printed, else if the %(else) atom is used, then
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+ everything after %(else) is printed. We ignore space when
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+ evaluating the string before %(then), this is useful when we
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+ use the %(HEAD) atom which prints either "*" or " " and we
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+ want to apply the 'if' condition only on the 'HEAD' ref.
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+
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In addition to the above, for commit and tag objects, the header
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field names (`tree`, `parent`, `object`, `type`, and `tag`) can
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be used to specify the value in the header field.
@@ -186,6 +196,14 @@ As a special case for the date-type fields, you may specify a format for
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the date by adding `:` followed by date format name (see the
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values the `--date` option to linkgit:git-rev-list[1] takes).
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+Some atoms like %(align) and %(if) always require a matching %(end).
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+We call them "opening atoms" and sometimes denote them as %($open).
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+
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+When a scripting language specific quoting is in effect, everything
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+between a top-level opening atom and its matching %(end) is evaluated
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+according to the semantics of the opening atom and only its result
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+from the top-level is quoted.
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+
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EXAMPLES
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--------
@@ -273,6 +291,22 @@ eval=`git for-each-ref --shell --format="$fmt" \
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eval "$eval"
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------------
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+
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+An example to show the usage of %(if)...%(then)...%(else)...%(end).
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+This prefixes the current branch with a star.
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+
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+------------
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+git for-each-ref --format="%(if)%(HEAD)%(then)* %(else) %(end)%(refname:short)" refs/heads/
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+------------
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+
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+
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+An example to show the usage of %(if)...%(then)...%(end).
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+This prints the authorname, if present.
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+
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+------------
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+git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Authored by: %(authorname)%(end)"
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+------------
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+
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SEE ALSO
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--------
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linkgit:git-show-ref[1]
ref-filter.c
+127
-7
@@ -22,6 +22,12 @@ struct align {
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unsigned int width;
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};
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+struct if_then_else {
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+ unsigned int then_atom_seen : 1,
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+ else_atom_seen : 1,
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+ condition_satisfied : 1;
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+};
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+
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/*
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* An atom is a valid field atom listed below, possibly prefixed with
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* a "*" to denote deref_tag().
@@ -214,6 +220,9 @@ static struct {
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{ "color", FIELD_STR, color_atom_parser },
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{ "align", FIELD_STR, align_atom_parser },
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{ "end" },
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+ { "if" },
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+ { "then" },
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+ { "else" },
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};
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#define REF_FORMATTING_STATE_INIT { 0, NULL }
@@ -221,7 +230,7 @@ static struct {
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struct ref_formatting_stack {
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struct ref_formatting_stack *prev;
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struct strbuf output;
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- void (*at_end)(struct ref_formatting_stack *stack);
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+ void (*at_end)(struct ref_formatting_stack **stack);
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void *at_end_data;
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};
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@@ -354,13 +363,14 @@ static void pop_stack_element(struct ref_formatting_stack **stack)
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*stack = prev;
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}
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-static void end_align_handler(struct ref_formatting_stack *stack)
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+static void end_align_handler(struct ref_formatting_stack **stack)
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{
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- struct align *align = (struct align *)stack->at_end_data;
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+ struct ref_formatting_stack *cur = *stack;
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+ struct align *align = (struct align *)cur->at_end_data;
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struct strbuf s = STRBUF_INIT;
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- strbuf_utf8_align(&s, align->position, align->width, stack->output.buf);
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- strbuf_swap(&stack->output, &s);
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+ strbuf_utf8_align(&s, align->position, align->width, cur->output.buf);
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+ strbuf_swap(&cur->output, &s);
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strbuf_release(&s);
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}
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@@ -374,6 +384,104 @@ static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_s
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new->at_end_data = &atomv->u.align;
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}
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+static void if_then_else_handler(struct ref_formatting_stack **stack)
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+{
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+ struct ref_formatting_stack *cur = *stack;
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+ struct ref_formatting_stack *prev = cur->prev;
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+ struct if_then_else *if_then_else = (struct if_then_else *)cur->at_end_data;
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+
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+ if (!if_then_else->then_atom_seen)
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+ die(_("format: %%(if) atom used without a %%(then) atom"));
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+
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+ if (if_then_else->else_atom_seen) {
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+ /*
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+ * There is an %(else) atom: we need to drop one state from the
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+ * stack, either the %(else) branch if the condition is satisfied, or
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+ * the %(then) branch if it isn't.
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+ */
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+ if (if_then_else->condition_satisfied) {
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+ strbuf_reset(&cur->output);
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+ pop_stack_element(&cur);
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+ } else {
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+ strbuf_swap(&cur->output, &prev->output);
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+ strbuf_reset(&cur->output);
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+ pop_stack_element(&cur);
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+ }
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+ } else if (!if_then_else->condition_satisfied) {
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+ /*
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+ * No %(else) atom: just drop the %(then) branch if the
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+ * condition is not satisfied.
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+ */
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+ strbuf_reset(&cur->output);
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+ }
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+
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+ *stack = cur;
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+ free(if_then_else);
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+}
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+
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+static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
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+{
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+ struct ref_formatting_stack *new;
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+ struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
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+
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+ push_stack_element(&state->stack);
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+ new = state->stack;
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+ new->at_end = if_then_else_handler;
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+ new->at_end_data = if_then_else;
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+}
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+
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+static int is_empty(const char *s)
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+{
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+ while (*s != '\0') {
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+ if (!isspace(*s))
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+ return 0;
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+ s++;
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+ }
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+ return 1;
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+}
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+
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+static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
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+{
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+ struct ref_formatting_stack *cur = state->stack;
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+ struct if_then_else *if_then_else = NULL;
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+
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+ if (cur->at_end == if_then_else_handler)
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+ if_then_else = (struct if_then_else *)cur->at_end_data;
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+ if (!if_then_else)
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+ die(_("format: %%(then) atom used without an %%(if) atom"));
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+ if (if_then_else->then_atom_seen)
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+ die(_("format: %%(then) atom used more than once"));
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+ if (if_then_else->else_atom_seen)
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+ die(_("format: %%(then) atom used after %%(else)"));
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+ if_then_else->then_atom_seen = 1;
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+ /*
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+ * If there exists non-empty string between the 'if' and
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+ * 'then' atom then the 'if' condition is satisfied.
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+ */
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+ if (cur->output.len && !is_empty(cur->output.buf))
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+ if_then_else->condition_satisfied = 1;
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+ strbuf_reset(&cur->output);
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+}
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+
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+static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
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+{
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+ struct ref_formatting_stack *prev = state->stack;
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+ struct if_then_else *if_then_else = NULL;
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+
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+ if (prev->at_end == if_then_else_handler)
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+ if_then_else = (struct if_then_else *)prev->at_end_data;
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+ if (!if_then_else)
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+ die(_("format: %%(else) atom used without an %%(if) atom"));
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+ if (!if_then_else->then_atom_seen)
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+ die(_("format: %%(else) atom used without a %%(then) atom"));
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+ if (if_then_else->else_atom_seen)
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+ die(_("format: %%(else) atom used more than once"));
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+ if_then_else->else_atom_seen = 1;
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+ push_stack_element(&state->stack);
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+ state->stack->at_end_data = prev->at_end_data;
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+ state->stack->at_end = prev->at_end;
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+}
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+
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static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
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{
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struct ref_formatting_stack *current = state->stack;
@@ -381,14 +489,17 @@ static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_sta
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if (!current->at_end)
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die(_("format: %%(end) atom used without corresponding atom"));
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- current->at_end(current);
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+ current->at_end(&state->stack);
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+
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+ /* Stack may have been popped within at_end(), hence reset the current pointer */
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+ current = state->stack;
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/*
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* Perform quote formatting when the stack element is that of
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* a supporting atom. If nested then perform quote formatting
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* only on the topmost supporting atom.
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*/
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- if (!state->stack->prev->prev) {
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+ if (!current->prev->prev) {
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quote_formatting(&s, current->output.buf, state->quote_style);
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strbuf_swap(¤t->output, &s);
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}
@@ -1049,6 +1160,15 @@ static void populate_value(struct ref_array_item *ref)
1160
} else if (!strcmp(name, "end")) {
1161
v->handler = end_atom_handler;
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continue;
1163
+ } else if (!strcmp(name, "if")) {
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+ v->handler = if_atom_handler;
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+ continue;
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+ } else if (!strcmp(name, "then")) {
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+ v->handler = then_atom_handler;
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+ continue;
1169
+ } else if (!strcmp(name, "else")) {
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+ v->handler = else_atom_handler;
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+ continue;
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} else
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continue;
1174
t/t6302-for-each-ref-filter.sh
+76
@@ -327,4 +327,80 @@ test_expect_success 'reverse version sort' '
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test_cmp expect actual
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'
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+test_expect_success 'improper usage of %(if), %(then), %(else) and %(end) atoms' '
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+ test_must_fail git for-each-ref --format="%(if)" &&
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+ test_must_fail git for-each-ref --format="%(then) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(else) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(if) %(else) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(if) %(then) %(then) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(then) %(else) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(if) %(else) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(if) %(then) %(else)" &&
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+ test_must_fail git for-each-ref --format="%(if) %(else) %(then) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(if) %(then) %(else) %(else) %(end)" &&
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+ test_must_fail git for-each-ref --format="%(if) %(end)"
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+'
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+
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+test_expect_success 'check %(if)...%(then)...%(end) atoms' '
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+ git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Author: %(authorname)%(end)" >actual &&
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+ cat >expect <<-\EOF &&
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+ refs/heads/master Author: A U Thor
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+ refs/heads/side Author: A U Thor
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+ refs/odd/spot Author: A U Thor
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+ refs/tags/annotated-tag
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+ refs/tags/doubly-annotated-tag
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+ refs/tags/doubly-signed-tag
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+ refs/tags/foo1.10 Author: A U Thor
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+ refs/tags/foo1.3 Author: A U Thor
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+ refs/tags/foo1.6 Author: A U Thor
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+ refs/tags/four Author: A U Thor
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+ refs/tags/one Author: A U Thor
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+ refs/tags/signed-tag
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+ refs/tags/three Author: A U Thor
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+ refs/tags/two Author: A U Thor
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+ EOF
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+ test_cmp expect actual
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+'
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+
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+test_expect_success 'check %(if)...%(then)...%(else)...%(end) atoms' '
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+ git for-each-ref --format="%(if)%(authorname)%(then)%(authorname)%(else)No author%(end): %(refname)" >actual &&
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+ cat >expect <<-\EOF &&
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+ A U Thor: refs/heads/master
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+ A U Thor: refs/heads/side
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+ A U Thor: refs/odd/spot
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+ No author: refs/tags/annotated-tag
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+ No author: refs/tags/doubly-annotated-tag
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+ No author: refs/tags/doubly-signed-tag
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+ A U Thor: refs/tags/foo1.10
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+ A U Thor: refs/tags/foo1.3
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+ A U Thor: refs/tags/foo1.6
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+ A U Thor: refs/tags/four
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+ A U Thor: refs/tags/one
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+ No author: refs/tags/signed-tag
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+ A U Thor: refs/tags/three
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+ A U Thor: refs/tags/two
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+ EOF
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+ test_cmp expect actual
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+'
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+test_expect_success 'ignore spaces in %(if) atom usage' '
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+ git for-each-ref --format="%(refname:short): %(if)%(HEAD)%(then)Head ref%(else)Not Head ref%(end)" >actual &&
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+ cat >expect <<-\EOF &&
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+ master: Head ref
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+ side: Not Head ref
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+ odd/spot: Not Head ref
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+ annotated-tag: Not Head ref
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+ doubly-annotated-tag: Not Head ref
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+ doubly-signed-tag: Not Head ref
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+ foo1.10: Not Head ref
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+ foo1.3: Not Head ref
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+ foo1.6: Not Head ref
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+ four: Not Head ref
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+ one: Not Head ref
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+ signed-tag: Not Head ref
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+ three: Not Head ref
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+ two: Not Head ref
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+ EOF
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+ test_cmp expect actual
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+'
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+
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test_done