[PATCH] gpg-interface: fix strip_cr_before_lf to only remove CR before LF

[DSAntonio08 <antonio.destefani08@gmail.com>]

The remove_cr_after() function was stripping all CR characters
unconditionally, even lone \r not followed by \n. This is incorrect
as only \r\n sequences (Windows line endings) should be normalized.

Fix the loop condition to skip \r only when immediately followed by
\n, and rename the function to strip_cr_before_lf to reflect its
actual behavior. Update both call sites and their comments accordingly.
---
 gpg-interface.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/gpg-interface.c b/gpg-interface.c
index dafd5371fa..87ae6503da 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -989,17 +989,13 @@ int sign_buffer(struct strbuf *buffer, struct strbuf *signature,
 	free(keyid_to_free);
 	return ret;
 }
-
-/*
- * Strip CR from the line endings, in case we are on Windows.
- * NEEDSWORK: make it trim only CRs before LFs and rename
- */
-static void remove_cr_after(struct strbuf *buffer, size_t offset)
+/* Strip CR before LF from the line endings, in case we are on Windows. */
+static void strip_cr_before_lf(struct strbuf *buffer, size_t offset)
 {
 	size_t i, j;
 
 	for (i = j = offset; i < buffer->len; i++) {
-		if (buffer->buf[i] != '\r') {
+		if (buffer->buf[i] != '\r' || (i + 1 < buffer->len && buffer->buf[i + 1] != '\n')) {
 			if (i != j)
 				buffer->buf[j] = buffer->buf[i];
 			j++;
@@ -1049,8 +1045,8 @@ static int sign_buffer_gpg(struct strbuf *buffer, struct strbuf *signature,
 	}
 	strbuf_release(&gpg_status);
 
-	/* Strip CR from the line endings, in case we are on Windows. */
-	remove_cr_after(signature, bottom);
+	/* Strip CR before LF from the line endings, in case we are on Windows. */
+	strip_cr_before_lf(signature, bottom);
 
 	return 0;
 }
@@ -1136,8 +1132,8 @@ static int sign_buffer_ssh(struct strbuf *buffer, struct strbuf *signature,
 			ssh_signature_filename.buf);
 		goto out;
 	}
-	/* Strip CR from the line endings, in case we are on Windows. */
-	remove_cr_after(signature, bottom);
+	/* Strip CR before LF from the line endings, in case we are on Windows. */
+	strip_cr_before_lf(signature, bottom);
 
 out:
 	if (key_file)
-- 
2.54.0