diff: handle missing new lines in trailing context If there is a missing new line in the context we currently miss it and fail to print the warning. This trips up patch and leads to failures. Catch these cases in for unidiff output and add a test case. ok stsp@

diff: Add API for consumers to check if diff is printable Programs using the libdiff API they can need to know if the diff contained anything that would be printed, or would be empty. Expose the same check that the output functions do as a function call. ok stsp@

add regress test for function prototype in hunk header

sync changes from got.git to implement headers-only mode for plain output

improve accuracy of function prototype in hunk headers Initial diff by Tom Jones with fixes from stsp. ok stsp@

fix updating of line-offsets output info in plain output mode reviewed by tom jones

sync diff_patience.c from got.git 336075a42a5ae0fa322db734c481d21998e82bb8

sync files from got.git 336075a42a5ae0fa322db734c481d21998e82bb8 ok tb@

fix build broken in previous commit 35eae7fa6b782ae1 Macro line was wrapped without continuation character. ok tb@

remove gcc ternary if extension ok stsp@

add support for classic diff(1) output; patch by Tom Jones

collect line type metadata when generating diff Similar to line offsets, create an array of line types (i.e., hunk, context, minus, plus) for each line output in the diff. ok stsp@

sync files from got.git 58e31a80da4f4a9e10eaea148672190f35107a47 ok stsp@

revert previous; got lib/blame.c needs diff_atom_hash_update()

make diff_atom_hash_update private to diff_atomize_text.c ok stsp@

reuse diff_atom_hash_update ok stsp@

less chatty regress ok stsp@

regress: look for the diff prog also inside obj/ ok stsp@

adjust the expected output so that regress passes again Note that test015 is still broken on OpenBSD with base patch(1). ok stsp@

ARRAY_LIST allocation optimisation Rather than realloc in fixed-sized blocks, use the 1.5 * allocated scheme when growing the array. This produces fewer allocations and up to 3x speedup on large diffs. ok stsp@

fix accounting for line endings in CRLF files There are two different subtles error in computing the end of line in diff_data_atomize_text_lines (one in per implementation, _fd and _mmap) that causes the '\n' of the '\r\n' case to be left out the current line. It causes strange bugs when diffing CRLF files, such as printing the "\ No newline at end of file" marker very often and showing the wrong offsets in the hunk headers. ok stsp@

add missing line offset information for unidiff output We forgot to generate line offset information for lines of the form: "Binary files %s and %s differ" Which is causing scrolling problems in tog's diff view. ok thomas_adam

fix a size_t multiplication overflow in diff_meyrs.c Found on an OpenBSD armv7 machine running Got regression tests: test_status_shows_no_mods_after_complete_merge Segmentation fault (core dumped) The problematic multiplication is kd_len * kd_len in diff_algo_myers() with kd_len set to 65537. (gdb) p (int)(65537 * 65537) $64 = 131073 (gdb) p (int)(65537 + 65537) $65 = 131074 (gdb) p (unsigned int)(size_t)(-1) $68 = 4294967295 (gdb) p (4294967295 / kd_len) $71 = 65535 Detect such overflow and run the fallback diff algorithm instead.

fix ed script diff output when lines are inserted at the top of a file

avoid writing just one character at a time in diff_output_lines() With input from ori@ and millert@