From: Jeff King <peff@peff.net>
Date: Wed, 13 Jan 2010 17:35:31 +0000 (-0500)
Subject: strbuf_expand: convert "%%" to "%"
X-Git-Tag: v1.7.0-rc0~72^2~5
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=0a0416a34a7ef5c64f4e0226371e4cab8c1ba982;p=git.git

strbuf_expand: convert "%%" to "%"

The only way to safely quote arbitrary text in a pretty-print user
format is to replace instances of "%" with "%x25". This is slightly
unreadable, and many users would expect "%%" to produce a single
"%", as that is what printf format specifiers do.

This patch converts "%%" to "%" for all users of strbuf_expand():

 (1) git-daemon interpolated paths

 (2) pretty-print user formats

 (3) merge driver command lines

Case (1) was already doing the conversion itself outside of
strbuf_expand(). Case (2) is the intended beneficiary of this patch.
Case (3) users probably won't notice, but as this is user-facing
behavior, consistently providing the quoting mechanism makes sense.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 53a9168ba..1686a54d2 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -134,6 +134,7 @@ The placeholders are:
 - '%C(...)': color specification, as described in color.branch.* config option
 - '%m': left, right or boundary mark
 - '%n': newline
+- '%%': a raw '%'
 - '%x00': print a byte from a hex code
 - '%w([<w>[,<i1>[,<i2>]]])': switch line wrapping, like the -w option of
   linkgit:git-shortlog[1].
diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt
index a0e0f850f..3b1da10f2 100644
--- a/Documentation/technical/api-strbuf.txt
+++ b/Documentation/technical/api-strbuf.txt
@@ -199,6 +199,10 @@ character if the letter `n` appears after a `%`.  The function returns
 the length of the placeholder recognized and `strbuf_expand()` skips
 over it.
 +
+The format `%%` is automatically expanded to a single `%` as a quoting
+mechanism; callers do not need to handle the `%` placeholder themselves,
+and the callback function will not be invoked for this placeholder.
++
 All other characters (non-percent and not skipped ones) are copied
 verbatim to the strbuf.  If the callback returned zero, meaning that the
 placeholder is unknown, then the percent sign is copied, too.
diff --git a/daemon.c b/daemon.c
index 5783e2401..51d9d6b8a 100644
--- a/daemon.c
+++ b/daemon.c
@@ -147,7 +147,6 @@ static char *path_ok(char *directory)
 			{ "IP", ip_address },
 			{ "P", tcp_port },
 			{ "D", directory },
-			{ "%", "%" },
 			{ NULL }
 		};
 
diff --git a/strbuf.c b/strbuf.c
index a6153dca2..6cbc1fcfd 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -227,6 +227,12 @@ void strbuf_expand(struct strbuf *sb, const char *format, expand_fn_t fn,
 			break;
 		format = percent + 1;
 
+		if (*format == '%') {
+			strbuf_addch(sb, '%');
+			format++;
+			continue;
+		}
+
 		consumed = fn(sb, format, context);
 		if (consumed)
 			format += consumed;
diff --git a/t/t6006-rev-list-format.sh b/t/t6006-rev-list-format.sh
index 571931588..b0047d3c6 100755
--- a/t/t6006-rev-list-format.sh
+++ b/t/t6006-rev-list-format.sh
@@ -19,6 +19,13 @@ test_cmp expect.$1 output.$1
 "
 }
 
+test_format percent %%h <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+%h
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+%h
+EOF
+
 test_format hash %H%n%h <<'EOF'
 commit 131a310eb913d107dd3c09a65d1651175898735d
 131a310eb913d107dd3c09a65d1651175898735d