Re: [PATCH 1/8] git-gui: rework handling of diff header

The fix in ca53c3f (Fix diff parsing for lines starting with "--" or "++",
2008-09-05) got a bug report from Johannes Sixt, that new files in the
index now looks like:

new file mode 100644

--- /dev/null
+++ b/foo

@@ -0,0 +1 @@
+foo

The introduced problem was that the 'in-diff-header'-flag was unconditially
disabled. Now it is only disabled when a hunk line is detected. And also
re-enabled when we encounter a new diff header.

The second part solves also the issue reported by me for diffs with file
type changes (i.e. the ''error: Unhandled 2 way diff marker: {d}"', which
comes from the second 'diff --git' line).

Reported-by: Johannes Sixt <redacted>
Reported-by: Bert Wesarg <redacted>
Signed-off-by: Bert Wesarg <redacted>

---

Cc: Johannes Sixt <redacted>
---
foo          |    1 +
lib/diff.tcl |   18 +++++++++++++++---
2 files changed, 16 insertions(+), 3 deletions(-)
create mode 100644 foo

diff --git a/foo b/foo
new file mode 100644
index 0000000..257cc56
--- /dev/null
+++ b/foo

@@ -0,0 +1 @@
+foo

diff --git a/lib/diff.tcl b/lib/diff.tcl
index 9d0dc07..dae6ca6 100644
--- a/lib/diff.tcl
+++ b/lib/diff.tcl

@@ -382,23 +382,35 @@ proc read_diff {fd conflict_size cont_info} {

		foreach {line markup} [parse_color_line $line] break
		set line [string map {\033 ^} $line]

-		# -- Cleanup uninteresting diff header lines.
+		# -- Check for start of diff header.
+		if {   [string match {diff --git *}      $line]
+		    || [string match {diff --cc *}       $line]
+		    || [string match {diff --combined *} $line]} {
+			set ::current_diff_inheader 1
+		}
+
+		# -- Check for end of diff header (any hunk line will do this).
		#
+		if {[regexp {^@@+ } $line]} {set ::current_diff_inheader 0}
+
		if {$::current_diff_inheader} {
+			append current_diff_header $line "\n"
+
+			# -- Cleanup uninteresting diff header lines.
+			#
			if {   [string match {diff --git *}      $line]
			    || [string match {diff --cc *}       $line]
			    || [string match {diff --combined *} $line]
			    || [string match {--- *}             $line]
			    || [string match {+++ *}             $line]} {
-				append current_diff_header $line "\n"
				continue
			}
		}
+
		if {[string match {index *} $line]} continue
		if {$line eq {deleted file mode 120000}} {
			set line "deleted symlink"
		}
-		set ::current_diff_inheader 0

		# -- Automatically detect if this is a 3 way diff.
		#