[PATCHv2 0/8] Add color test for range-diff, simplify diff.c

addressed all of Erics feedback:
* reworded commit messages
* dropped q_to_tab and use cat instead
* use -\EOF isntead of -EOF

Thanks, Stefan

Stefan Beller (8):
  test_decode_color: understand FAINT and ITALIC
  t3206: add color test for range-diff --dual-color
  diff.c: simplify caller of emit_line_0
  diff.c: reorder arguments for emit_line_ws_markup
  diff.c: add set_sign to emit_line_0
  diff: use emit_line_0 once per line
  diff.c: compute reverse locally in emit_line_0
  diff.c: rewrite emit_line_0 more understandably

 diff.c                  | 94 +++++++++++++++++++++++------------------
 t/t3206-range-diff.sh   | 39 +++++++++++++++++
 t/test-lib-functions.sh |  2 +
 3 files changed, 93 insertions(+), 42 deletions(-)

./git-range-diff ws_cleanup-ontop-range-diff-2@{2.hours.ago}...HEAD >>0000-cover-letter.patch
[dropped changes to range-diff itself]
13:  a02ea020ae7 ! 13:  16f71b43f48 t3206: add color test for range-diff --dual-color
    @@ -2,9 +2,7 @@
     
         t3206: add color test for range-diff --dual-color
     
    -    The 'expect'ed outcome is taken by running the 'range-diff |decode';
    -    it is not meant as guidance, rather as a documentation of the current
    -    situation.
    +    The 'expect'ed outcome has been taken by running the 'range-diff | decode'.
     
         Signed-off-by: Stefan Beller <sbeller@google.com>
     
    @@ -15,8 +13,8 @@
      	test_cmp expected actual
      '
      
    -+test_expect_success 'simple coloring' '
    -+	q_to_tab >expect <<-EOF &&
    ++test_expect_success 'dual-coloring' '
    ++	cat >expect <<-\EOF &&
     +	<YELLOW>1:  a4b3333 = 1:  f686024 s/5/A/<RESET>
     +	<RED>2:  f51d370 <RESET><YELLOW>!<RESET><GREEN> 2:  4ab067d<RESET><YELLOW> s/4/A/<RESET>
     +	    <REVERSE><CYAN>@@ -2,6 +2,8 @@<RESET>
14:  c8734075229 = 14:  abd1ec80608 diff.c: simplify caller of emit_line_0
15:  ba98acffcda = 15:  bc29037f4f0 diff.c: reorder arguments for emit_line_ws_markup
16:  5a576baeb49 ! 16:  8f6ee340f1e diff.c: add set_sign to emit_line_0
    @@ -5,9 +5,10 @@
         For now just change the signature, we'll reason about the actual
         change in a follow up patch.
     
    -    Pass set_sign (which is output before the sign) and set that is setting
    -    the color after the sign. Hence, promote any 'set's to set_sign as
    -    we want to have color before the sign for now.
    +    Pass 'set_sign' (which is output before the sign) and 'set' which
    +    controls the color after the first character. Hence, promote any
    +    'set's to 'set_sign' as we want to have color before the sign
    +    for now.
     
         Signed-off-by: Stefan Beller <sbeller@google.com>
     
17:  4e2d5a4c7f3 = 17:  0ab5920a9ab diff: use emit_line_0 once per line
18:  460713e1c3c = 18:  2d05ebdd280 diff.c: compute reverse locally in emit_line_0
19:  e442d722b7f ! 19:  001e6042d81 diff.c: rewrite emit_line_0 more understandably
    @@ -7,9 +7,9 @@
         and set_sign, but let's defer that to a later patch.
     
         'first' used be output always no matter if it was 0, but that got lost
    -    got lost at e8c285c4f9c (diff: add an internal option to dual-color
    -    diffs of diffs, 2018-07-21), as there we broadened the meaning of 'first'
    -    to also signal an early return.
    +    at "diff: add an internal option to dual-color diffs of diffs",
    +    2018-07-21), as there we broadened the meaning of 'first' to also
    +    signal an early return.
     
         The change in 'emit_line' makes sure that 'first' is never content, but
         always under our control, a sign or special character in the beginning