[PATCH 02/12] wrapper.c: add a new function unlink_or_msg

[Ronnie Sahlberg <sahlberg@google.com>]

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 git-compat-util.h |  6 ++++++
 wrapper.c         | 18 ++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/git-compat-util.h b/git-compat-util.h
index b6f03b3..426bc98 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -704,12 +704,18 @@ void git_qsort(void *base, size_t nmemb, size_t size,
 #endif
 #endif
 
+#include "strbuf.h"
+
 /*
  * Preserves errno, prints a message, but gives no warning for ENOENT.
  * Always returns the return value of unlink(2).
  */
 int unlink_or_warn(const char *path);
 /*
+ * Like unlink_or_warn but populates a strbuf
+ */
+int unlink_or_msg(const char *file, struct strbuf *err);
+/*
  * Likewise for rmdir(2).
  */
 int rmdir_or_warn(const char *path);
diff --git a/wrapper.c b/wrapper.c
index 740e193..74a0cc0 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -438,6 +438,24 @@ static int warn_if_unremovable(const char *op, const char *file, int rc)
 	return rc;
 }
 
+int unlink_or_msg(const char *file, struct strbuf *err)
+{
+	if (err) {
+		int rc = unlink(file);
+		int save_errno = errno;
+
+		if (rc < 0 && errno != ENOENT) {
+			strbuf_addf(err, "unable to unlink %s: %s",
+				    file, strerror(errno));
+			errno = save_errno;
+			return -1;
+		}
+		return 0;
+	}
+
+	return unlink_or_warn(file);
+}
+
 int unlink_or_warn(const char *file)
 {
 	return warn_if_unremovable("unlink", file, unlink(file));
-- 
2.0.1.527.gc6b782e