[PATCH v2 05/10] ref-filter: adopt get_head_description() from branch.c

[Karthik Nayak <karthik.188@gmail.com>]

Copy the implementation of get_head_description() from branch.c.  This
gives a description of the HEAD ref if called. This is used as the
refname for the HEAD ref whenever the FILTER_REFS_DETACHED_HEAD option
is used. Make it public because we need it to calculate the length of
the HEAD refs description in branch.c:calc_maxwidth() when we port
branch.c to use ref-filter APIs.

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>
---
 builtin/branch.c |  4 ++++
 ref-filter.c     | 38 ++++++++++++++++++++++++++++++++++++--
 ref-filter.h     |  2 ++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/builtin/branch.c b/builtin/branch.c
index b7a60f4..67ef9f1 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -355,6 +355,10 @@ static void add_verbose_info(struct strbuf *out, struct ref_array_item *item,
 	strbuf_release(&subject);
 }
 
+/*
+ * This is duplicated in ref-filter.c, will be removed when we adopt
+ * ref-filter's printing APIs.
+ */
 static char *get_head_description(void)
 {
 	struct strbuf desc = STRBUF_INIT;
diff --git a/ref-filter.c b/ref-filter.c
index de4d451..a3cc3af 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -13,6 +13,7 @@
 #include "utf8.h"
 #include "git-compat-util.h"
 #include "version.h"
+#include "wt-status.h"
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
 
@@ -916,6 +917,37 @@ static inline char *copy_advance(char *dst, const char *src)
 	return dst;
 }
 
+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) {
+		/* TRANSLATORS: make sure these match _("HEAD detached at ")
+		   and _("HEAD detached from ") in wt-status.c */
+		if (state.detached_at)
+			strbuf_addf(&desc, _("(HEAD detached at %s)"),
+				state.detached_from);
+		else
+			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);
+}
+
 /*
  * Parse the object referred by ref, and grab needed value.
  */
@@ -954,9 +986,11 @@ static void populate_value(struct ref_array_item *ref)
 			name++;
 		}
 
-		if (starts_with(name, "refname"))
+		if (starts_with(name, "refname")) {
 			refname = ref->refname;
-		else if (starts_with(name, "symref"))
+			if (ref->kind & FILTER_REFS_DETACHED_HEAD)
+				refname = get_head_description();
+		} else if (starts_with(name, "symref"))
 			refname = ref->symref ? ref->symref : "";
 		else if (starts_with(name, "upstream")) {
 			const char *branch_name;
diff --git a/ref-filter.h b/ref-filter.h
index 14d435e..4aea594 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -106,5 +106,7 @@ int parse_opt_ref_sorting(const struct option *opt, const char *arg, int unset);
 struct ref_sorting *ref_default_sorting(void);
 /*  Function to parse --merged and --no-merged options */
 int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset);
+/*  Get the current HEAD's description */
+char *get_head_description(void);
 
 #endif /*  REF_FILTER_H  */
-- 
2.6.0