Merge branch 'maint' into tj/imap-send-remove-unusedtj/maint-imap-send-remove-unused

* maint: (18123 commits)
  documentation fix: git difftool uses diff tools, not merge tools.
  Git 1.7.7.4
  Makefile: add missing header file dependencies
  notes merge: eliminate OUTPUT macro
  mailmap: xcalloc mailmap_info
  name-rev --all: do not even attempt to describe non-commit object
  Git 1.7.7.3
  docs: Update install-doc-quick
  docs: don't mention --quiet or --exit-code in git-log(1)
  Git 1.7.7.2
  t7511: avoid use of reserved filename on Windows.
  clone: Quote user supplied path in a single quote pair
  read-cache.c: fix index memory allocation
  make the sample pre-commit hook script reject names with newlines, too
  Reindent closing bracket using tab instead of spaces
  Git 1.7.7.1
  RelNotes/1.7.7.1: setgid bit patch is about fixing "git init" via Makefile setting
  gitweb: fix regression when filtering out forks
  Almost ready for 1.7.7.1
  pack-objects: don't traverse objects unnecessarily
  ...

Conflicts:
	imap-send.c

1 files changed, 137 insertions, 27 deletions

diff --git a/pkt-line.c b/pkt-line.c
index bb3bab05cd..5a04984ea3 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -1,11 +1,56 @@
 #include "cache.h"
 #include "pkt-line.h"
 
+static const char *packet_trace_prefix = "git";
+static const char trace_key[] = "GIT_TRACE_PACKET";
+
+void packet_trace_identity(const char *prog)
+{
+	packet_trace_prefix = xstrdup(prog);
+}
+
+static void packet_trace(const char *buf, unsigned int len, int write)
+{
+	int i;
+	struct strbuf out;
+
+	if (!trace_want(trace_key))
+		return;
+
+	/* +32 is just a guess for header + quoting */
+	strbuf_init(&out, len+32);
+
+	strbuf_addf(&out, "packet: %12s%c ",
+		    packet_trace_prefix, write ? '>' : '<');
+
+	if ((len >= 4 && !prefixcmp(buf, "PACK")) ||
+	    (len >= 5 && !prefixcmp(buf+1, "PACK"))) {
+		strbuf_addstr(&out, "PACK ...");
+		unsetenv(trace_key);
+	}
+	else {
+		/* XXX we should really handle printable utf8 */
+		for (i = 0; i < len; i++) {
+			/* suppress newlines */
+			if (buf[i] == '\n')
+				continue;
+			if (buf[i] >= 0x20 && buf[i] <= 0x7e)
+				strbuf_addch(&out, buf[i]);
+			else
+				strbuf_addf(&out, "\\%o", buf[i]);
+		}
+	}
+
+	strbuf_addch(&out, '\n');
+	trace_strbuf(trace_key, &out);
+	strbuf_release(&out);
+}
+
 /*
  * Write a packetized stream, where each line is preceded by
  * its length (including the header) as a 4-byte hex number.
  * A length of 'zero' means end of stream (and a length of 1-3
- * would be an error). 
+ * would be an error).
  *
  * This is all pretty stupid, but we use this packetized line
  * format to make a streaming format possible without ever
@@ -16,19 +61,21 @@
  * The writing side could use stdio, but since the reading
  * side can't, we stay with pure read/write interfaces.
  */
-static void safe_write(int fd, const void *buf, unsigned n)
+ssize_t safe_write(int fd, const void *buf, ssize_t n)
 {
+	ssize_t nn = n;
 	while (n) {
 		int ret = xwrite(fd, buf, n);
 		if (ret > 0) {
-			buf += ret;
+			buf = (char *) buf + ret;
 			n -= ret;
 			continue;
 		}
 		if (!ret)
 			die("write error (disk full?)");
-		die("write error (%s)", strerror(errno));
+		die_errno("write error");
 	}
+	return nn;
 }
 
 /*
@@ -37,20 +84,24 @@ static void safe_write(int fd, const void *buf, unsigned n)
  */
 void packet_flush(int fd)
 {
+	packet_trace("0000", 4, 1);
 	safe_write(fd, "0000", 4);
 }
 
+void packet_buf_flush(struct strbuf *buf)
+{
+	packet_trace("0000", 4, 1);
+	strbuf_add(buf, "0000", 4);
+}
+
 #define hex(a) (hexchar[(a) & 15])
-void packet_write(int fd, const char *fmt, ...)
+static char buffer[1000];
+static unsigned format_packet(const char *fmt, va_list args)
 {
-	static char buffer[1000];
 	static char hexchar[] = "0123456789abcdef";
-	va_list args;
 	unsigned n;
 
-	va_start(args, fmt);
 	n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
-	va_end(args);
 	if (n >= sizeof(buffer)-4)
 		die("protocol error: impossibly long line");
 	n += 4;
@@ -58,32 +109,46 @@ void packet_write(int fd, const char *fmt, ...)
 	buffer[1] = hex(n >> 8);
 	buffer[2] = hex(n >> 4);
 	buffer[3] = hex(n);
+	packet_trace(buffer+4, n-4, 1);
+	return n;
+}
+
+void packet_write(int fd, const char *fmt, ...)
+{
+	va_list args;
+	unsigned n;
+
+	va_start(args, fmt);
+	n = format_packet(fmt, args);
+	va_end(args);
 	safe_write(fd, buffer, n);
 }
 
-static void safe_read(int fd, void *buffer, unsigned size)
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 {
-	int n = 0;
+	va_list args;
+	unsigned n;
 
-	while (n < size) {
-		int ret = xread(fd, buffer + n, size - n);
-		if (ret < 0)
-			die("read error (%s)", strerror(errno));
-		if (!ret)
-			die("unexpected EOF");
-		n += ret;
-	}
+	va_start(args, fmt);
+	n = format_packet(fmt, args);
+	va_end(args);
+	strbuf_add(buf, buffer, n);
 }
 
-int packet_read_line(int fd, char *buffer, unsigned size)
+static void safe_read(int fd, void *buffer, unsigned size)
 {
-	int n;
-	unsigned len;
-	char linelen[4];
+	ssize_t ret = read_in_full(fd, buffer, size);
+	if (ret < 0)
+		die_errno("read error");
+	else if (ret < size)
+		die("The remote end hung up unexpectedly");
+}
 
-	safe_read(fd, linelen, 4);
+static int packet_length(const char *linelen)
+{
+	int n;
+	int len = 0;
 
-	len = 0;
 	for (n = 0; n < 4; n++) {
 		unsigned char c = linelen[n];
 		len <<= 4;
@@ -99,14 +164,59 @@ int packet_read_line(int fd, char *buffer, unsigned size)
 			len += c - 'A' + 10;
 			continue;
 		}
-		die("protocol error: bad line length character");
+		return -1;
 	}
-	if (!len)
+	return len;
+}
+
+int packet_read_line(int fd, char *buffer, unsigned size)
+{
+	int len;
+	char linelen[4];
+
+	safe_read(fd, linelen, 4);
+	len = packet_length(linelen);
+	if (len < 0)
+		die("protocol error: bad line length character: %.4s", linelen);
+	if (!len) {
+		packet_trace("0000", 4, 0);
 		return 0;
+	}
 	len -= 4;
 	if (len >= size)
 		die("protocol error: bad line length %d", len);
 	safe_read(fd, buffer, len);
 	buffer[len] = 0;
+	packet_trace(buffer, len, 0);
+	return len;
+}
+
+int packet_get_line(struct strbuf *out,
+	char **src_buf, size_t *src_len)
+{
+	int len;
+
+	if (*src_len < 4)
+		return -1;
+	len = packet_length(*src_buf);
+	if (len < 0)
+		return -1;
+	if (!len) {
+		*src_buf += 4;
+		*src_len -= 4;
+		packet_trace("0000", 4, 0);
+		return 0;
+	}
+	if (*src_len < len)
+		return -2;
+
+	*src_buf += 4;
+	*src_len -= 4;
+	len -= 4;
+
+	strbuf_add(out, *src_buf, len);
+	*src_buf += len;
+	*src_len -= len;
+	packet_trace(out->buf, out->len, 0);
 	return len;
 }