fix(diff): use mmfile_t in linematch

Problem:

Linematch used to use strchr to navigate a string, however strchr does
not supoprt embedded NULs.

Solution:

Use `mmfile_t` instead of `char *` in linematch and introduce `strnchr()`.

Also remove heap allocations from `matching_char_iwhite()`

Fixes: #30505

1 files changed, 13 insertions, 13 deletions

diff --git a/runtime/doc/lua.txt b/runtime/doc/lua.txt
index 29b35d69a0..cbe283065d 100644
--- a/runtime/doc/lua.txt
+++ b/runtime/doc/lua.txt
@@ -713,8 +713,8 @@ vim.diff({a}, {b}, {opts})                                        *vim.diff()*
     Parameters: ~
       • {a}     (`string`) First string to compare
       • {b}     (`string`) Second string to compare
-      • {opts}  (`table`) Optional parameters:
-                • {on_hunk}
+      • {opts}  (`table?`) Optional parameters:
+                • {on_hunk}?
                   (`fun(start_a: integer, count_a: integer, start_b: integer, count_b: integer): integer`)
                   Invoked for each hunk in the diff. Return a negative number
                   to cancel the callback for any remaining hunks. Arguments:
@@ -722,33 +722,33 @@ vim.diff({a}, {b}, {opts})                                        *vim.diff()*
                   • `count_a` (`integer`): Hunk size in {a}.
                   • `start_b` (`integer`): Start line of hunk in {b}.
                   • `count_b` (`integer`): Hunk size in {b}.
-                • {result_type} (`'unified'|'indices'`, default: `'unified'`)
+                • {result_type}? (`'unified'|'indices'`, default: `'unified'`)
                   Form of the returned diff:
                   • `unified`: String in unified format.
                   • `indices`: Array of hunk locations. Note: This option is
                     ignored if `on_hunk` is used.
-                • {linematch} (`boolean|integer`) Run linematch on the
+                • {linematch}? (`boolean|integer`) Run linematch on the
                   resulting hunks from xdiff. When integer, only hunks upto
                   this size in lines are run through linematch. Requires
                   `result_type = indices`, ignored otherwise.
-                • {algorithm} (`'myers'|'minimal'|'patience'|'histogram'`,
+                • {algorithm}? (`'myers'|'minimal'|'patience'|'histogram'`,
                   default: `'myers'`) Diff algorithm to use. Values:
                   • `myers`: the default algorithm
                   • `minimal`: spend extra time to generate the smallest
                     possible diff
                   • `patience`: patience diff algorithm
                   • `histogram`: histogram diff algorithm
-                • {ctxlen} (`integer`) Context length
-                • {interhunkctxlen} (`integer`) Inter hunk context length
-                • {ignore_whitespace} (`boolean`) Ignore whitespace
-                • {ignore_whitespace_change} (`boolean`) Ignore whitespace
+                • {ctxlen}? (`integer`) Context length
+                • {interhunkctxlen}? (`integer`) Inter hunk context length
+                • {ignore_whitespace}? (`boolean`) Ignore whitespace
+                • {ignore_whitespace_change}? (`boolean`) Ignore whitespace
                   change
-                • {ignore_whitespace_change_at_eol} (`boolean`) Ignore
+                • {ignore_whitespace_change_at_eol}? (`boolean`) Ignore
                   whitespace change at end-of-line.
-                • {ignore_cr_at_eol} (`boolean`) Ignore carriage return at
+                • {ignore_cr_at_eol}? (`boolean`) Ignore carriage return at
                   end-of-line
-                • {ignore_blank_lines} (`boolean`) Ignore blank lines
-                • {indent_heuristic} (`boolean`) Use the indent heuristic for
+                • {ignore_blank_lines}? (`boolean`) Ignore blank lines
+                • {indent_heuristic}? (`boolean`) Use the indent heuristic for
                   the internal diff library.
 
     Return: ~