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[PATCH v2 10/11] sha1_name: reorganize get_sha1_basic()

From
Felipe Contreras <felipe.contreras@gmail.com>
Date
May 7, 2013, 21:55 UTC
Message-ID
<1367963711-8722-11-git-send-email-felipe.contreras@gmail.com>
In-Reply-To
<1367963711-8722-1-git-send-email-felipe.contreras@gmail.com>

Through the years the functionality to handle @{-N} and @{u} has moved around the code, and as a result, code that once made sense, doesn't any more.

There is no need to call this function recursively with the branch of @{-N} substituted because dwim_{ref,log} already replaces it.

However, there's one corner-case where @{-N} resolves to a detached HEAD, in which case we wouldn't get any ref back.

So we parse the nth-prior manually, and deal with it depending on weather it's a SHA-1, or a ref.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 sha1_name.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/sha1_name.c b/sha1_name.c
index 0acc6e0..c512c69 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -431,13 +431,14 @@ static inline int upstream_mark(const char *string, int len)
 }
 
 static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
+static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf);
 
 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 {
 	static const char *warn_msg = "refname '%.*s' is ambiguous.";
 	char *real_ref = NULL;
 	int refs_found = 0;
-	int at, reflog_len;
+	int at, reflog_len, nth_prior = 0;
 
 	if (len == 40 && !get_sha1_hex(str, sha1))
 		return 0;
@@ -447,6 +448,10 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 	if (len && str[len-1] == '}') {
 		for (at = len-4; at >= 0; at--) {
 			if (str[at] == '@' && str[at+1] == '{') {
+				if (at == 0 && str[2] == '-') {
+					nth_prior = 1;
+					continue;
+				}
 				if (!upstream_mark(str + at, len - at)) {
 					reflog_len = (len-1) - (at+2);
 					len = at;
@@ -460,19 +465,22 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 	if (len && ambiguous_path(str, len))
 		return -1;
 
-	if (!len && reflog_len) {
+	if (nth_prior) {
 		struct strbuf buf = STRBUF_INIT;
-		int ret;
-		/* try the @{-N} syntax for n-th checkout */
-		ret = interpret_branch_name(str, &buf);
-		if (ret > 0)
-			/* substitute this branch name and restart */
-			return get_sha1_1(buf.buf, buf.len, sha1, 0);
-		else if (ret == 0)
-			return -1;
+		int detached;
+
+		if (interpret_nth_prior_checkout(str, &buf) > 0) {
+			detached = (buf.len == 40 && !get_sha1_hex(buf.buf, sha1));
+			strbuf_release(&buf);
+			if (detached)
+				return 0;
+		}
+	}
+
+	if (!len && reflog_len)
 		/* allow "@{...}" to mean the current branch reflog */
 		refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
-	} else if (reflog_len)
+	else if (reflog_len)
 		refs_found = dwim_log(str, len, sha1, &real_ref);
 	else
 		refs_found = dwim_ref(str, len, sha1, &real_ref);
-- 
1.8.3.rc0.401.g45bba44
Previous: Felipe ContrerasNext: Ramkumar Ramachandra
Message 15 of 26 in “sha1_name: improvements”
  1. 00/11 sha1_name: improvementsFelipe Contreras, May 7, 2013
  2. 01/11 tests: at-combinations: simplify setupFelipe Contreras, May 7, 2013
  3. 02/11 tests: at-combinations: check ref names directlyFelipe Contreras, May 7, 2013
  4. Junio C HamanoMay 8, 2013
  5. Felipe ContrerasMay 8, 2013
  6. 03/11 tests: at-combinations: improve nonsense()Felipe Contreras, May 7, 2013
  7. Junio C HamanoMay 8, 2013
  8. Felipe ContrerasMay 8, 2013
  9. 04/11 tests: at-combinations: increase coverageFelipe Contreras, May 7, 2013
  10. 05/11 tests: at-combinations: @{N} versus HEAD@{N}Felipe Contreras, May 7, 2013
  11. 06/11 sha1_name: remove no-opFelipe Contreras, May 7, 2013
  12. 07/11 sha1_name: remove unnecessary bracesFelipe Contreras, May 7, 2013
  13. 08/11 sha1_name: avoid Yoda conditionsFelipe Contreras, May 7, 2013
  14. 09/11 sha1_name: don't waste cycles in the @-parsing loopFelipe Contreras, May 7, 2013
  15. 10/11 sha1_name: reorganize get_sha1_basic()Felipe Contreras, May 7, 2013
  16. Ramkumar RamachandraMay 8, 2013
  17. Felipe ContrerasMay 8, 2013
  18. Junio C HamanoMay 8, 2013
  19. Junio C HamanoMay 8, 2013
  20. Felipe ContrerasMay 8, 2013
  21. Junio C HamanoMay 8, 2013
  22. Felipe ContrerasMay 8, 2013
  23. 11/11 sha1_name: check @{-N} errors soonerFelipe Contreras, May 7, 2013
  24. Felipe ContrerasMay 7, 2013
  25. Junio C HamanoMay 8, 2013
  26. Ramkumar RamachandraMay 8, 2013

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