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[PATCH 2/6] shortlog: use strbufs to read from stdin

From
Jeff King <peff@peff.net>
Date
Jan 15, 2016, 17:08 UTC
Message-ID
<20160115170835.GB21102@sigill.intra.peff.net>
In-Reply-To
<20160115170627.GA20983@sigill.intra.peff.net>

We currently use fixed-size buffers with fgets(), which could lead to incorrect results in the unlikely event that a line had something like "Author:" at exactly its 1024th character.

But it's easy to convert this to a strbuf, and because we can reuse the same buffer through the loop, we don't even pay the extra allocation cost.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/shortlog.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/builtin/shortlog.c b/builtin/shortlog.c
index fe9fa2f..bb2ee5b 100644
--- a/builtin/shortlog.c
+++ b/builtin/shortlog.c
@@ -112,20 +112,23 @@ static int match_ident_header(const char *candidate, const char *header,
 
 static void read_from_stdin(struct shortlog *log)
 {
-	char author[1024], oneline[1024];
+	struct strbuf author = STRBUF_INIT;
+	struct strbuf oneline = STRBUF_INIT;
 
-	while (fgets(author, sizeof(author), stdin) != NULL) {
+	while (strbuf_getline(&author, stdin, '\n') != EOF) {
 		const char *v;
-		if (!match_ident_header(author, "author", &v))
+		if (!match_ident_header(author.buf, "author", &v))
 			continue;
-		while (fgets(oneline, sizeof(oneline), stdin) &&
-		       oneline[0] != '\n')
+		while (strbuf_getline(&oneline, stdin, '\n') != EOF &&
+		       oneline.len)
 			; /* discard headers */
-		while (fgets(oneline, sizeof(oneline), stdin) &&
-		       oneline[0] == '\n')
+		while (strbuf_getline(&oneline, stdin, '\n') != EOF &&
+		       !oneline.len)
 			; /* discard blanks */
-		insert_one_record(log, v, oneline);
+		insert_one_record(log, v, oneline.buf);
 	}
+	strbuf_release(&author);
+	strbuf_release(&oneline);
 }
 
 void shortlog_add_commit(struct shortlog *log, struct commit *commit)
-- 
2.7.0.244.g0701a9d
Previous: Jeff KingNext: Jeff King
Message 17 of 22 in “shortlog fixes and optimizations”
  1. 0/6 shortlog fixes and optimizationsJeff King, Jan 15, 2016
  2. 1/6 shortlog: match both "Author:" and "author" on stdinJeff King, Jan 15, 2016
  3. Eric SunshineJan 15, 2016
  4. Jeff KingJan 18, 2016
  5. Jeff KingJan 18, 2016
  6. Junio C HamanoJan 18, 2016
  7. 0/6 shortlog fixes and optimizationsJeff King, Jan 18, 2016
  8. 1/6 shortlog: match both "Author:" and "author" on stdinJeff King, Jan 18, 2016
  9. 2/6 shortlog: use strbufs to read from stdinJeff King, Jan 18, 2016
  10. 3/6 shortlog: replace hand-parsing of author with pretty-printerJeff King, Jan 18, 2016
  11. Jeff KingJan 18, 2016
  12. Jeff KingJan 18, 2016
  13. Junio C HamanoJan 19, 2016
  14. 4/6 shortlog: optimize "--summary" modeJeff King, Jan 18, 2016
  15. 5/6 shortlog: optimize out useless "<none>" normalizationJeff King, Jan 18, 2016
  16. 6/6 shortlog: optimize out useless string listJeff King, Jan 18, 2016
  17. 2/6 shortlog: use strbufs to read from stdinJeff King, Jan 15, 2016
  18. 3/6 shortlog: replace hand-parsing of author with pretty-printerJeff King, Jan 15, 2016
  19. 4/6 shortlog: optimize "--summary" modeJeff King, Jan 15, 2016
  20. 5/6 shortlog: optimize out useless "<none>" normalizationJeff King, Jan 15, 2016
  21. 6/6 shortlog: optimize out useless string listJeff King, Jan 15, 2016
  22. Junio C HamanoJan 15, 2016

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