[PATCH 09/15] for-each-ref: teach verify_format() about pretty's syntax

[Ramkumar Ramachandra <artagnon@gmail.com>]

From: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

Pretty format accepts either ' ', '+' or '-' after '%' and before the
placeholder name to modify certain behaviors. Teach verify_format()
about this so that it finds atom "upstream" in, for example,
'% (upstream)'. This is important because verify_format populates
used_atom, which get_value() and populate_value() later rely on.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 builtin/for-each-ref.c | 15 +++++++++------
 pretty.c               |  4 ++++
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index 576a882..f8a3880 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -150,7 +150,7 @@ static int parse_atom(const char *atom, const char *ep)
 /*
  * In a format string, find the next occurrence of %(atom).
  */
-static const char *find_next(const char *cp)
+static const char *find_next(const char *cp, int pretty)
 {
 	while (*cp) {
 		if (*cp == '%') {
@@ -160,6 +160,9 @@ static const char *find_next(const char *cp)
 			 */
 			if (cp[1] == '(')
 				return cp;
+			else if (pretty && cp[1] && cp[2] == '(' &&
+				 strchr(" +-", cp[1])) /* see format_commit_item() */
+				return cp + 1;
 			else if (cp[1] == '%')
 				cp++; /* skip over two % */
 			/* otherwise this is a singleton, literal % */
@@ -173,10 +176,10 @@ static const char *find_next(const char *cp)
  * Make sure the format string is well formed, and parse out
  * the used atoms.
  */
-static int verify_format(const char *format)
+static int verify_format(const char *format, int pretty)
 {
 	const char *cp, *sp;
-	for (cp = format; *cp && (sp = find_next(cp)); ) {
+	for (cp = format; *cp && (sp = find_next(cp, pretty)); ) {
 		const char *ep = strchr(sp, ')');
 		if (!ep)
 			return error("malformed format string %s", sp);
@@ -935,7 +938,7 @@ static void show_ref(struct strbuf *sb, struct refinfo *info,
 {
 	const char *cp, *sp, *ep;
 
-	for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
+	for (cp = format; *cp && (sp = find_next(cp, 0)); cp = ep + 1) {
 		ep = strchr(sp, ')');
 		if (cp < sp)
 			emit(sb, cp, sp);
@@ -1093,8 +1096,8 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 	}
 	if (format != default_format && pretty)
 		die("--format and --pretty cannot be used together");
-	if ((pretty && verify_format(pretty)) ||
-	    (!pretty && verify_format(format)))
+	if ((pretty && verify_format(pretty, 1)) ||
+	    (!pretty && verify_format(format, 0)))
 		usage_with_options(for_each_ref_usage, opts);
 
 	if (!sort)
diff --git a/pretty.c b/pretty.c
index 816aa32..28c0a72 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1439,6 +1439,10 @@ static size_t format_commit_item(struct strbuf *sb, /* in UTF-8 */
 		ADD_SP_BEFORE_NON_EMPTY
 	} magic = NO_MAGIC;
 
+	/*
+	 * Note: any modification in what placeholder[0] contains
+	 * should be redone in builtin/for-each-ref.c:find_next().
+	 */
 	switch (placeholder[0]) {
 	case '-':
 		magic = DEL_LF_BEFORE_EMPTY;
-- 
1.8.3.GIT