[v4,2/6] version: refactor redact_non_printables()

Commit Message

Christian Couder Jan. 27, 2025, 3:16 p.m. UTC

From: Usman Akinyemi <[e-mail]>

The git_user_agent_sanitized() function performs some sanitizing to
avoid special characters being sent over the line and possibly messing
up with the protocol or with the parsing on the other side.

Let's extract this sanitizing into a new redact_non_printables() function,
as we will want to reuse it in a following patch.

For now the new redact_non_printables() function is still static as
it's only needed locally.

While at it, let's use strbuf_detach() to explicitly detach the string
contained by the 'buf' strbuf.

Mentored-by: Christian Couder <[e-mail]>
Signed-off-by: Usman Akinyemi <[e-mail]>
---
 version.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

Patch

diff --git a/version.c b/version.c
index c9192a5beb..4f37b4499d 100644
--- a/version.c
+++ b/version.c
@@ -12,6 +12,19 @@ 
 const char git_version_string[] = GIT_VERSION;
 const char git_built_from_commit_string[] = GIT_BUILT_FROM_COMMIT;
 
+/*
+ * Trim and replace each character with ascii code below 32 or above
+ * 127 (included) using a dot '.' character.
+ */
+static void redact_non_printables(struct strbuf *buf)
+{
+	strbuf_trim(buf);
+	for (size_t i = 0; i < buf->len; i++) {
+		if (!isprint(buf->buf[i]) || buf->buf[i] == ' ')
+			buf->buf[i] = '.';
+	}
+}
+
 const char *git_user_agent(void)
 {
 	static const char *agent = NULL;
@@ -33,12 +46,8 @@  const char *git_user_agent_sanitized(void)
 		struct strbuf buf = STRBUF_INIT;
 
 		strbuf_addstr(&buf, git_user_agent());
-		strbuf_trim(&buf);
-		for (size_t i = 0; i < buf.len; i++) {
-			if (!isprint(buf.buf[i]) || buf.buf[i] == ' ')
-				buf.buf[i] = '.';
-		}
-		agent = buf.buf;
+		redact_non_printables(&buf);
+		agent = strbuf_detach(&buf, NULL);
 	}
 
 	return agent;