1 files changed, 63 insertions, 32 deletions

diff --git a/write_or_die.c b/write_or_die.c
index 5c4bc8515a..e7afe7a295 100644
--- a/write_or_die.c
+++ b/write_or_die.c
@@ -1,57 +1,88 @@
 #include "cache.h"
 
-int read_in_full(int fd, void *buf, size_t count)
+static void check_pipe(int err)
 {
-	char *p = buf;
-	ssize_t total = 0;
-
-	while (count > 0) {
-		ssize_t loaded = xread(fd, p, count);
-		if (loaded <= 0)
-			return total ? total : loaded;
-		count -= loaded;
-		p += loaded;
-		total += loaded;
+	if (err == EPIPE) {
+		signal(SIGPIPE, SIG_DFL);
+		raise(SIGPIPE);
+		/* Should never happen, but just in case... */
+		exit(141);
 	}
-
-	return total;
 }
 
-int write_in_full(int fd, const void *buf, size_t count)
+/*
+ * Some cases use stdio, but want to flush after the write
+ * to get error handling (and to get better interactive
+ * behaviour - not buffering excessively).
+ *
+ * Of course, if the flush happened within the write itself,
+ * we've already lost the error code, and cannot report it any
+ * more. So we just ignore that case instead (and hope we get
+ * the right error code on the flush).
+ *
+ * If the file handle is stdout, and stdout is a file, then skip the
+ * flush entirely since it's not needed.
+ */
+void maybe_flush_or_die(FILE *f, const char *desc)
 {
-	const char *p = buf;
-	ssize_t total = 0;
+	static int skip_stdout_flush = -1;
+	struct stat st;
+	char *cp;
 
-	while (count > 0) {
-		ssize_t written = xwrite(fd, p, count);
-		if (written < 0)
-			return -1;
-		if (!written) {
-			errno = ENOSPC;
-			return -1;
+	if (f == stdout) {
+		if (skip_stdout_flush < 0) {
+			cp = getenv("GIT_FLUSH");
+			if (cp)
+				skip_stdout_flush = (atoi(cp) == 0);
+			else if ((fstat(fileno(stdout), &st) == 0) &&
+				 S_ISREG(st.st_mode))
+				skip_stdout_flush = 1;
+			else
+				skip_stdout_flush = 0;
 		}
-		count -= written;
-		p += written;
-		total += written;
+		if (skip_stdout_flush && !ferror(f))
+			return;
+	}
+	if (fflush(f)) {
+		check_pipe(errno);
+		die_errno("write failure on '%s'", desc);
+	}
+}
+
+void fprintf_or_die(FILE *f, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = vfprintf(f, fmt, ap);
+	va_end(ap);
+
+	if (ret < 0) {
+		check_pipe(errno);
+		die_errno("write error");
 	}
+}
 
-	return total;
+void fsync_or_die(int fd, const char *msg)
+{
+	if (fsync(fd) < 0) {
+		die_errno("fsync error on '%s'", msg);
+	}
 }
 
 void write_or_die(int fd, const void *buf, size_t count)
 {
 	if (write_in_full(fd, buf, count) < 0) {
-		if (errno == EPIPE)
-			exit(0);
-		die("write error (%s)", strerror(errno));
+		check_pipe(errno);
+		die_errno("write error");
 	}
 }
 
 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
 {
 	if (write_in_full(fd, buf, count) < 0) {
-		if (errno == EPIPE)
-			exit(0);
+		check_pipe(errno);
 		fprintf(stderr, "%s: write error (%s)\n",
 			msg, strerror(errno));
 		return 0;