runtime(syntax-tests): Allow for folded and wrapped lines in syntax test files
The current implementation falls short for syntax test files
on two accounts:
1. With folded lines -- some lines before folded lines are
unnecessarily repeated in generated dump files because
closed folded lines are always treated as opened for the
cursor to move _in_ instead of to move _over_ them.
2. With wrapped lines (longer than 75 columns) -- some lines
are omitted in generated dump files because calculations
for the cursor progress and its movement commands only
refer to file lines and not their layout within a 20x75
buffer (less &cmdheight).
As an alternative, we abandon deterministic (and inaccurate
at times) calculations for the cursor progress and, instead,
advance the cursor by as much as before for a single dump
file, but now rely on marking the last visible line and
additional movement to position lines at desired offsets,
carefully preserving compatibility for the &scrolloff and
&ruler values inherited from defaults.vim. The parent Vim
process will keep track of progress through a syntax test
file made by its child process ("terminal") by reading the
rightmost end of the ruler line from the terminal buffer,
looking for " All " or " Bot " for its cue to finish dump
file generation.
With these changes applied, the lossless line length limit
will be raised from 75 to 1425 (for a 19x75 view) columns.
Also, prefer "lastline" to "truncate" for &display; hiding
the content of any last _long_ line in a view goes against
the purpose of syntax file testing -- all lines should be
recorded.
related: #15150
fixes: #14245
Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/testdir/dumps/c_07.dump b/runtime/syntax/testdir/dumps/c_07.dump
new file mode 100644
index 0000000..22be2f8
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/c_07.dump
@@ -0,0 +1,20 @@
+|#+0#e000e06#ffffff0|e|l|s|e| +0#0000000&@69
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|v|i|m|_|m|a|i|n|2|(|)|;| @51
+|#+0#e000e06&|e|n|d|i|f| +0#0000000&@68
+>}| @73
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|2|3|,|1| @8|B|o|t|