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2022-09-28merge-ort: fix segmentation fault in read-only repositoriesJohannes Schindelin
If the blob/tree objects cannot be written, we really need the merge operations to fail, and not to continue (and then try to access the tree object which is however still set to `NULL`). Let's stop ignoring the return value of `write_object_file()` and `write_tree()` and set `clean = -1` in the error case. Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-29Merge branch 'en/ort-unused-code-removal'Junio C Hamano
Code clean-up. * en/ort-unused-code-removal: merge-ort: remove code obsoleted by other changes
2022-08-25Merge branch 'en/submodule-merge-messages-fixes'Junio C Hamano
Further update the help messages given while merging submodules. * en/submodule-merge-messages-fixes: merge-ort: provide helpful submodule update message when possible merge-ort: avoid surprise with new sub_flag variable merge-ort: remove translator lego in new "submodule conflict suggestion" submodule merge: update conflict error message
2022-08-19merge-ort: remove code obsoleted by other changesElijah Newren
Commit 66b209b86a ("merge-ort: implement CE_SKIP_WORKTREE handling with conflicted entries", 2021-03-20) added some code for merge-ort to handle conflicted and skip_worktree entries in general. Included in this was an ugly hack for dealing with present-despite-skipped entries and a testcase (t6428.2) specific to that hack, since at that time users could accidentally get files into that state when using a sparse checkout. However, with the merging of 82386b4496 ("Merge branch 'en/present-despite-skipped'", 2022-03-09), that class of problems was addressed globally and in a much cleaner way. As such, the present-despite-skipped hack in merge-ort is no longer needed and can simply be removed. No additional testcase is needed here; t6428.2 was written to test the necessary functionality and is being kept. The fact that this test continues to pass despite the code being removed shows that the extra code is no longer necessary. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-18merge-ort: provide helpful submodule update message when possibleElijah Newren
In commit 4057523a40 ("submodule merge: update conflict error message", 2022-08-04), a more detailed message was provided when submodules conflict, in order to help users know how to resolve those conflicts. There were a couple situations for which a different message would be more appropriate, but that commit left handling those for future work. Unfortunately, that commit would check if any submodules were of the type that it didn't know how to explain, and, if so, would avoid providing the more detailed explanation even for the submodules it did know how to explain. Change this to have the code print the helpful messages for the subset of submodules it knows how to explain. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-18merge-ort: avoid surprise with new sub_flag variableElijah Newren
Commit 4057523a40 ("submodule merge: update conflict error message", 2022-08-04) added a sub_flag variable that is used to store a value from enum conflict_and_info_types, but initializes it with a value of -1 that does not correspond to any of the conflict_and_info_types. The code may never set it to a valid value and yet still use it, which can be surprising when reading over the code at first. Initialize it instead to the generic CONFLICT_SUBMODULE_FAILED_TO_MERGE value, which is still distinct from the two values we need to special case. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-18merge-ort: remove translator lego in new "submodule conflict suggestion"Elijah Newren
In commit 4057523a40 ("submodule merge: update conflict error message", 2022-08-04), the new "submodule conflict suggestion" code was translating 6 different pieces of the new message and then used carefully crafted logic to allow stitching it back together with special formatting. Keep the components of the message together as much as possible, so that: * we reduce the number of things translators have to translate * translators have more control over the format of the output * the code is much easier for developers to understand too Also, reformat some comments running beyond the 80th column while at it. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-08Merge branch 'js/ort-clean-up-after-failed-merge'Junio C Hamano
Plug memory leaks in the failure code path in the "merge-ort" merge strategy backend. * js/ort-clean-up-after-failed-merge: merge-ort: do leave trace2 region even if checkout fails merge-ort: clean up after failed merge
2022-08-04submodule merge: update conflict error messageCalvin Wan
When attempting to merge in a superproject with conflicting submodule pointers that cannot be fast-forwarded or trivially resolved, the merge fails and Git prints an error message that accurately describes the failure, but does not provide steps for the user to resolve the error. Git is left in a conflicted state, which requires the user to: 1. merge submodules or update submodules to an already existing commit that reflects the merge 2. add submodules changes to the superproject 3. finish merging superproject These steps are non-obvious for newer submodule users to figure out based on the error message and neither `git submodule status` nor `git status` provide any useful pointers. Update error message to provide steps to resolve submodule merge conflict. Future work could involve adding an advice flag to the message. Although the message is long, it also has the id of the submodule commit that needs to be merged, which could be useful information for the user. Additionally, 5 merge failures that resulted in an early return have been updated to reflect the status of the merge. 1. Null merge base (null o): CONFLICT_SUBMODULE_NULL_MERGE_BASE added as a new conflict type and will print updated error message. 2. Null merge side a (null a): BUG(). See [1] for discussion 3. Null merge side b (null b): BUG(). See [1] for discussion 4. Submodule not checked out: added NEEDSWORK bit 5. Submodule commits not present: added NEEDSWORK bit The errors with a NEEDSWORK bit deserve a more detailed explanation of how to resolve them. See [2] for more context. [1] https://lore.kernel.org/git/CABPp-BE0qGwUy80dmVszkJQ+tcpfLRW0OZyErymzhZ9+HWY1mw@mail.gmail.com/ [2] https://lore.kernel.org/git/xmqqpmhjjwo9.fsf@gitster.g/ Signed-off-by: Calvin Wan <calvinwan@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-31merge-ort: do leave trace2 region even if checkout failsJohannes Schindelin
In 557ac0350d9 (merge-ort: begin performance work; instrument with trace2_region_* calls, 2021-01-23), we added Trace2 instrumentation, but in the error path that returns early, we forgot to tell Trace2 that we're leaving the region. Let's fix that. Pointed-out-by: Elijah Newren <newren@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-31merge-ort: clean up after failed mergeJohannes Schindelin
In 9fefce68dc8 (merge-ort: basic outline for merge_switch_to_result(), 2020-12-13), we added functionality to lay down the result of a merge on disk. But we forgot to release the data structures in case `unpack_trees()` failed to run properly. This was pointed out by the `linux-leaks` job in our CI runs. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-18Merge branch 'en/merge-dual-dir-renames-fix'Junio C Hamano
Fixes a long-standing corner case bug around directory renames in the merge-ort strategy. * en/merge-dual-dir-renames-fix: merge-ort: fix issue with dual rename and add/add conflict merge-ort: shuffle the computation and cleanup of potential collisions merge-ort: make a separate function for freeing struct collisions merge-ort: small cleanups of check_for_directory_rename t6423: add tests of dual directory rename plus add/add conflict
2022-07-06merge-ort: fix issue with dual rename and add/add conflictElijah Newren
There is code in both merge-recursive and merge-ort for avoiding doubly transitive renames (i.e. one side renames directory A/ -> B/, and the other side renames directory B/ -> C/), because this combination would otherwise make a mess for new files added to A/ on the first side and wondering which directory they end up in -- especially if there were even more renames such as the first side renaming C/ -> D/. In such cases, it just turns "off" directory rename detection for the higher order transitive cases. The testcases added in t6423 a couple commits ago are slightly different but similar in principle. They involve a similar case of paired renaming but instead of A/ -> B/ and B/ -> C/, the second side renames a leading directory of B/ to C/. And both sides add a new file somewhere under the directory that the other side will rename. While the new files added start within different directories and thus could logically end up within different directories, it is weird for a file on one side to end up where the other one started and not move along with it. So, let's just turn off directory rename detection in this case as well. Another way to look at this is that if the source name involved in a directory rename on one side is the target name of a directory rename operation for a file from the other side, then we avoid the doubly transitive rename. (More concretely, if a directory rename on side D wants to rename a file on side E from OLD_NAME -> NEW_NAME, and side D already had a file named NEW_NAME, and a directory rename on side E wants to rename side D's NEW_NAME -> NEWER_NAME, then we turn off the directory rename detection for NEW_NAME to prevent the NEW_NAME -> NEWER_NAME rename, and instead end up with an add/add conflict on NEW_NAME.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06merge-ort: shuffle the computation and cleanup of potential collisionsElijah Newren
Run compute_collisions() for renames on both sides of history before any calls to collect_renames(), and do not free the computed collisions until after both calls to collect_renames(). This is just a code reorganization at this point that doesn't make sense on its own, but will permit us to use the computed collision info from both sides within each call to collect_renames() in a subsequent commit. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06merge-ort: make a separate function for freeing struct collisionsElijah Newren
This commit makes no functional changes, it's just some code movement in preparation for later changes. Signed-off-by: Elijah Newren <newren@palantir.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06merge-ort: small cleanups of check_for_directory_renameElijah Newren
No functional changes, just some preparatory cleanups. Suggested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Elijah Newren <newren@palantir.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22merge-ort: optionally produce machine-readable outputElijah Newren
With the new `detailed` parameter, a new mode can be triggered when displaying the merge messages: The `detailed` mode prints NUL-delimited fields of the following form: <path-count> NUL <path>... NUL <conflict-type> NUL <message> The `<path-count>` field determines how many `<path>` fields there are. The intention of this mode is to support server-side operations, where worktree-less merges can lead to conflicts and depending on the type and/or path count, the caller might know how to handle said conflict. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22merge-ort: store more specific conflict informationElijah Newren
It is all fine and dandy for a regular Git command that is intended to be run interactively to produce a bunch of messages upon an error. However, in `merge-ort`'s case, we want to call the command e.g. in server-side software, where the actual error messages are not quite as interesting as machine-readable, immutable terms that describe the exact nature of any given conflict. With this patch, the `merge-ort` machinery records the exact type (as specified via an `enum` value) as well as the involved path(s) together with the conflict's message. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22merge-ort: make `path_messages` a strmap to a string_listJohannes Schindelin
This allows us once again to get away with less data copying. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22merge-ort: store messages in a list, not in a single strbufJohannes Schindelin
To prepare for using the `merge-ort` machinery in server operations, we cannot simply produce a free-form string that combines a variable-length list of messages. Instead, we need to list them one by one. The natural fit for this is a `string_list`. We will subsequently add even more information in the `util` attribute of the string list items. Based-on-a-patch-by: Elijah Newren <newren@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22merge-ort: remove command-line-centric submodule message from merge-ortElijah Newren
There was one case in merge-ort that would call path_msg() multiple times for the same logical conflict, and it was in order to give advice about how to resolve a conflict. This advice does not make as much sense with remerge-diff, or with merge-tree being invoked by a GitHub GUI for resolution of messages, and is making it hard to provide which-logical-conflict-affects-which-paths information in a machine parseable way to a higher level caller of merge-tree. Let's simply remove this informational message. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22merge-ort: provide a merge_get_conflicted_files() helper functionElijah Newren
After a merge, this function allows the user to extract the same information that would be printed by `ls-files -u`, which means files with their mode, oid, and stage. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22merge-ort: split out a separate display_update_messages() functionElijah Newren
This patch includes no new code; it simply moves a bunch of lines into a new function. As such, there are no functional changes. This is just a preparatory step to allow the printed messages to be handled differently by other callers, such as in `git merge-tree --write-tree`. (Patch best viewed with --color-moved --color-moved-ws=allow-indentation-change to see that it is a simple code movement.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-07Merge branch 'ab/plug-leak-in-revisions'Junio C Hamano
Plug the memory leaks from the trickiest API of all, the revision walker. * ab/plug-leak-in-revisions: (27 commits) revisions API: add a TODO for diff_free(&revs->diffopt) revisions API: have release_revisions() release "topo_walk_info" revisions API: have release_revisions() release "date_mode" revisions API: call diff_free(&revs->pruning) in revisions_release() revisions API: release "reflog_info" in release revisions() revisions API: clear "boundary_commits" in release_revisions() revisions API: have release_revisions() release "prune_data" revisions API: have release_revisions() release "grep_filter" revisions API: have release_revisions() release "filter" revisions API: have release_revisions() release "cmdline" revisions API: have release_revisions() release "mailmap" revisions API: have release_revisions() release "commits" revisions API users: use release_revisions() for "prune_data" users revisions API users: use release_revisions() with UNLEAK() revisions API users: use release_revisions() in builtin/log.c revisions API users: use release_revisions() in http-push.c revisions API users: add "goto cleanup" for release_revisions() stash: always have the owner of "stash_info" free it revisions API users: use release_revisions() needing REV_INFO_INIT revision.[ch]: document and move code declared around "init" ...
2022-05-20Merge branch 'ep/maint-equals-null-cocci'Junio C Hamano
Introduce and apply coccinelle rule to discourage an explicit comparison between a pointer and NULL, and applies the clean-up to the maintenance track. * ep/maint-equals-null-cocci: tree-wide: apply equals-null.cocci tree-wide: apply equals-null.cocci contrib/coccinnelle: add equals-null.cocci
2022-05-02Merge branch 'ep/maint-equals-null-cocci' for maint-2.35Junio C Hamano
* ep/maint-equals-null-cocci: tree-wide: apply equals-null.cocci contrib/coccinnelle: add equals-null.cocci
2022-05-02tree-wide: apply equals-null.cocciJunio C Hamano
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-13revisions API users: add straightforward release_revisions()Ævar Arnfjörð Bjarmason
Add a release_revisions() to various users of "struct rev_list" in those straightforward cases where we only need to add the release_revisions() call to the end of a block, and don't need to e.g. refactor anything to use a "goto cleanup" pattern. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16Merge branch 'ab/string-list-count-in-size-t'Junio C Hamano
Count string_list items in size_t, not "unsigned int". * ab/string-list-count-in-size-t: string-list API: change "nr" and "alloc" to "size_t" gettext API users: don't explicitly cast ngettext()'s "n"
2022-03-16Merge branch 'ab/object-file-api-updates'Junio C Hamano
Object-file API shuffling. * ab/object-file-api-updates: object-file API: pass an enum to read_object_with_reference() object-file.c: add a literal version of write_object_file_prepare() object-file API: have hash_object_file() take "enum object_type" object API: rename hash_object_file_literally() to write_*() object-file API: split up and simplify check_object_signature() object API users + docs: check <0, not !0 with check_object_signature() object API docs: move check_object_signature() docs to cache.h object API: correct "buf" v.s. "map" mismatch in *.c and *.h object-file API: have write_object_file() take "enum object_type" object-file API: add a format_object_header() function object-file API: return "void", not "int" from hash_object_file() object-file.c: split up declaration of unrelated variables
2022-03-13Merge branch 'en/merge-ort-align-verbosity-with-recursive'Junio C Hamano
Align the level of verbose output from the ort backend during inner merge to that of the recursive backend. * en/merge-ort-align-verbosity-with-recursive: merge-ort: exclude messages from inner merges by default
2022-03-07string-list API: change "nr" and "alloc" to "size_t"Ævar Arnfjörð Bjarmason
Change the "nr" and "alloc" members of "struct string_list" to use "size_t" instead of "nr". On some platforms the size of an "unsigned int" will be smaller than a "size_t", e.g. a 32 bit unsigned v.s. 64 bit unsigned. As "struct string_list" is a generic API we use in a lot of places this might cause overflows. As one example: code in "refs.c" keeps track of the number of refs with a "size_t", and auxiliary code in builtin/remote.c in get_ref_states() appends those to a "struct string_list". While we're at it split the "nr" and "alloc" in string-list.h across two lines, which is the case for most such struct member declarations (e.g. in "strbuf.h" and "strvec.h"). Changing e.g. "int i" to "size_t i" in run_and_feed_hook() isn't strictly necessary, and there are a lot more cases where we'll use a local "int", "unsigned int" etc. variable derived from the "nr" in the "struct string_list". But in that case as well as add_wrapped_shortlog_msg() in builtin/shortlog.c we need to adjust the printf format referring to "nr" anyway, so let's also change the other variables referring to it. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-06Merge branch 'en/merge-ort-plug-leaks'Junio C Hamano
Leakfix. * en/merge-ort-plug-leaks: merge-ort: fix small memory leak in unique_path() merge-ort: fix small memory leak in detect_and_process_renames()
2022-03-01merge-ort: exclude messages from inner merges by defaultElijah Newren
merge-recursive would only report messages from inner merges when the GIT_MERGE_VERBOSITY was set to 5. Do the same for merge-ort. Note that somewhat reverts 0d83d8240d ("merge-ort: mark conflict/warning messages from inner merges as omittable", 2022-02-02) based on two facts: * This commit basically removes the showing of messages from inner merges as well, at least by default. The only difference is that users can request to get them back by turning up the verbosity. * Messages from inner merges are specially annotated since 4a3d86e1bb ("merge-ort: make informational messages from recursive merges clearer", 2022-02-17). The ability to distinguish them from outer merge comments make them less problematic to include, and easier for humans to parse. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-25object-file API: have write_object_file() take "enum object_type"Ævar Arnfjörð Bjarmason
Change the write_object_file() function to take an "enum object_type" instead of a "const char *type". Its callers either passed {commit,tree,blob,tag}_type and can pass the corresponding OBJ_* type instead, or were hardcoding strings like "blob". This avoids the back & forth fragility where the callers of write_object_file() would have the enum type, and convert it themselves via type_name(). We do have to now do that conversion ourselves before calling write_object_file_prepare(), but those codepaths will be similarly adjusted in subsequent commits. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-20merge-ort: fix small memory leak in unique_path()Elijah Newren
The struct strmap paths member of merge_options_internal is perhaps the most central data structure to all of merge-ort. Because all the paths involved in the merge need to be kept until the merge is complete, this "paths" data structure traditionally took responsibility for owning all the allocated paths. When the merge is over, those paths were free()d as part of free()ing this strmap. In commit 6697ee01b5d3 (merge-ort: switch our strmaps over to using memory pools, 2021-07-30), we changed the allocations for pathnames to come from a memory pool. That meant the ownership changed slightly; there were no individual free() calls to make, instead the memory pool owned all those paths and they were free()d all at once. Unfortunately unique_path() was written presuming the pre-memory-pool model, and allocated a path on the heap and left it in the strmap for later free()ing. Modify it to return a path allocated from the memory pool instead. Note that there's one instance -- in record_conflicted_index_entries() -- where the returned string from unique_path() was only used very temporarily and thus had been immediately free()'d. This codepath was associated with an ugly skip-worktree workaround that has since been better fixed by the in-flight en/present-despite-skipped topic. This workaround probably makes sense to excise once that topic merges down, but for now, just remove the immediate free() and allow the returned string to be free()d when the memory pool is released. This fixes the following memory leak as reported by valgrind: ==PID== 65 bytes in 1 blocks are definitely lost in loss record 79 of 134 ==PID== at 0xADDRESS: malloc ==PID== by 0xADDRESS: realloc ==PID== by 0xADDRESS: xrealloc (wrapper.c:126) ==PID== by 0xADDRESS: strbuf_grow (strbuf.c:98) ==PID== by 0xADDRESS: strbuf_vaddf (strbuf.c:394) ==PID== by 0xADDRESS: strbuf_addf (strbuf.c:335) ==PID== by 0xADDRESS: unique_path (merge-ort.c:733) ==PID== by 0xADDRESS: process_entry (merge-ort.c:3678) ==PID== by 0xADDRESS: process_entries (merge-ort.c:4037) ==PID== by 0xADDRESS: merge_ort_nonrecursive_internal (merge-ort.c:4621) ==PID== by 0xADDRESS: merge_ort_internal (merge-ort.c:4709) ==PID== by 0xADDRESS: merge_incore_recursive (merge-ort.c:4760) ==PID== by 0xADDRESS: merge_ort_recursive (merge-ort-wrappers.c:57) ==PID== by 0xADDRESS: try_merge_strategy (merge.c:753) Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-20merge-ort: fix small memory leak in detect_and_process_renames()Elijah Newren
detect_and_process_renames() detects renames on both sides of history and then combines these into a single diff_queue_struct. The combined diff_queue_struct needs to be able to hold the renames found on either side, and since it knows the (maximum) size it needs, it pre-emptively grows the array to the appropriate size: ALLOC_GROW(combined.queue, renames->pairs[1].nr + renames->pairs[2].nr, combined.alloc); It then collects the items from each side: collect_renames(opt, &combined, MERGE_SIDE1, ...) collect_renames(opt, &combined, MERGE_SIDE2, ...) Note, though, that collect_renames() sometimes determines that some pairs are unnecessary and does not include them in the combined array. When it is done, detect_and_process_renames() frees this memory: if (combined.nr) { ... free(combined.queue); } The problem is that sometimes even when there are pairs, none of them are necessary. Instead of checking combined.nr, just remove the if-check; free() knows to skip NULL pointers. This change fixes the following memory leak, as reported by valgrind: ==PID== 192 bytes in 1 blocks are definitely lost in loss record 107 of 134 ==PID== at 0xADDRESS: malloc ==PID== by 0xADDRESS: realloc ==PID== by 0xADDRESS: xrealloc (wrapper.c:126) ==PID== by 0xADDRESS: detect_and_process_renames (merge-ort.c:3134) ==PID== by 0xADDRESS: merge_ort_nonrecursive_internal (merge-ort.c:4610) ==PID== by 0xADDRESS: merge_ort_internal (merge-ort.c:4709) ==PID== by 0xADDRESS: merge_incore_recursive (merge-ort.c:4760) ==PID== by 0xADDRESS: merge_ort_recursive (merge-ort-wrappers.c:57) ==PID== by 0xADDRESS: try_merge_strategy (merge.c:753) ==PID== by 0xADDRESS: cmd_merge (merge.c:1676) ==PID== by 0xADDRESS: run_builtin (git.c:461) ==PID== by 0xADDRESS: handle_builtin (git.c:713) ==PID== by 0xADDRESS: run_argv (git.c:780) ==PID== by 0xADDRESS: cmd_main (git.c:911) ==PID== by 0xADDRESS: main (common-main.c:52) Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17merge-ort: make informational messages from recursive merges clearerElijah Newren
This is another simple change with a long explanation... merge-recursive and merge-ort are both based on the same recursive idea: if there is more than one merge base, merge the merge bases (which may require first merging the merge bases of the merges bases, etc.). The depth of the inner merge is recorded via a variable called "call_depth", which we'll bring up again later. Naturally, the inner merges themselves can have conflicts and various messages generated about those files. merge-recursive immediately prints to stdout as it goes, at the risk of printing multiple conflict notices for the same path separated far apart from each other with many intervenining conflict notices for other paths between them. And this is true even if there are no inner merges involved. An example of this was given in [1] and apparently caused some confusion: CONFLICT (rename/add): Rename A->B in HEAD. B added in otherbranch ...dozens of conflicts for OTHER paths... CONFLICT (content): Merge conflicts in B In contrast, merge-ort collects messages and stores them by path so that it can print them grouped by path. Thus, the same case handled by merge-ort would have output of the form: CONFLICT (rename/add): Rename A->B in HEAD. B added in otherbranch CONFLICT (content): Merge conflicts in B ...dozens of conflicts for OTHER paths... This is generally helpful, but does make a separate bug more problematic. In particular, while merge-recursive might report the following for a recursive merge: Auto-merging dir.c Auto-merging midx.c CONFLICT (content): Merge conflict in midx.c Auto-merging diff.c Auto-merging dir.c CONFLICT (content): Merge conflict in dir.c merge-ort would instead report: Auto-merging diff.c Auto-merging dir.c Auto-merging dir.c CONFLICT (content): Merge conflict in dir.c Auto-merging midx.c CONFLICT (content): Merge conflict in midx.c The fact that messages for the same file are together is probably helpful in general, but with the indentation missing for the inner merge it unfortunately serves to confuse. This probably would lead users to wonder: * Why is Git reporting that "dir.c" is being merged twice? * If midx.c has conflicts, why do I not see any when I open up the file and why are no conflicts shown in the index? Fix this output confusion by changing the output to clearly differentiate the messages for outer merges from the ones for inner merges, changing the above output from merge-ort to: Auto-merging diff.c From inner merge: Auto-merging dir.c Auto-merging dir.c CONFLICT (content): Merge conflict in dir.c From inner merge: Auto-merging midx.c From inner merge: CONFLICT (content): Merge conflict in midx.c (Note: the number of spaces after the 'From inner merge:' is 2*call_depth). One other thing to note here, that I didn't notice until typing up this commit message, is that merge-recursive does not print any messages from the inner merges by default; the extra verbosity has to be requested. merge-ort currently has no verbosity controls and always prints these. We may also want to change that, but for now, just make the output clearer with these extra markings and indentation. [1] https://lore.kernel.org/git/CAGyf7-He4in8JWUh9dpAwvoPkQz9hr8nCBpxOxhZEd8+jtqTpg@mail.gmail.com/ Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-16Merge branch 'en/remerge-diff'Junio C Hamano
"git log --remerge-diff" shows the difference from mechanical merge result and the result that is actually recorded in a merge commit. * en/remerge-diff: diff-merges: avoid history simplifications when diffing merges merge-ort: mark conflict/warning messages from inner merges as omittable show, log: include conflict/warning messages in --remerge-diff headers diff: add ability to insert additional headers for paths merge-ort: format messages slightly different for use in headers merge-ort: mark a few more conflict messages as omittable merge-ort: capture and print ll-merge warnings in our preferred fashion ll-merge: make callers responsible for showing warnings log: clean unneeded objects during `log --remerge-diff` show, log: provide a --remerge-diff capability
2022-02-09Merge branch 'en/plug-leaks-in-merge'Junio C Hamano
Leakfix. * en/plug-leaks-in-merge: merge: fix memory leaks in cmd_merge() merge-ort: fix memory leak in merge_ort_internal()
2022-02-09Merge branch 'en/merge-ort-restart-optim-fix'Junio C Hamano
The merge-ort misbehaved when merge.renameLimit configuration is set too low and failed to find all renames. * en/merge-ort-restart-optim-fix: merge-ort: avoid assuming all renames detected
2022-02-02merge-ort: mark conflict/warning messages from inner merges as omittableElijah Newren
A recursive merge involves merging the merge bases of the two branches being merged. Such an inner merge can itself generate conflict notices. While such notices may be useful when initially trying to create a merge, they seem to just be noise when investigating merges later with --remerge-diff. (Especially when both sides of the outer merge resolved the conflict the same way leading to no overall conflict.) Remove them. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02show, log: include conflict/warning messages in --remerge-diff headersElijah Newren
Conflicts such as modify/delete, rename/rename, or file/directory are not representable via content conflict markers, and the normal output messages notifying users about these were dropped with --remerge-diff. While we don't want these messages randomly shown before the commit and diff headers, we do want them to still be shown; include them as part of the diff headers instead. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02merge-ort: format messages slightly different for use in headersElijah Newren
When users run git show --remerge-diff $MERGE_COMMIT or git log -p --remerge-diff ... stdout is not an appropriate location to dump conflict messages, but we do want to provide them to users. We will include them in the diff headers instead...but for that to work, we need for any multiline messages to replace newlines with both a newline and a space. Add a new flag to signal when we want these messages modified in such a fashion, and use it in path_msg() to modify these messages this way. Also, allow a special prefix to be specified for these headers. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02merge-ort: mark a few more conflict messages as omittableElijah Newren
path_msg() has the ability to mark messages as omittable, designed for remerge-diff where we'll instead be showing conflict messages as diff headers for a subsequent diff. While all these messages are very useful when trying to create a merge initially, early use with the --remerge-diff feature (the only user of this omittable conflict message capability), suggests that the particular messages marked in this commit are just noise when trying to see what changes users made to create a merge commit. Mark them as omittable. Note that there were already a few messages marked as omittable in merge-ort when doing a remerge-diff, because the development of --remerge-diff preceded the upstreaming of merge-ort and I was trying to ensure merge-ort could handle all the necessary requirements. See commit c5a6f65527 ("merge-ort: add modify/delete handling and delayed output processing", 2020-12-03) for the initial details. For some examples of already-marked-as-omittable messages, see either "Auto-merging <path>" or some of the submodule update hints. This commit just adds two more messages that should also be omittable. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02merge-ort: capture and print ll-merge warnings in our preferred fashionElijah Newren
Instead of immediately printing ll-merge warnings to stderr, we save them in our output strbuf. Besides allowing us to move these warnings to a special file for --remerge-diff, this has two other benefits for regular merges done by merge-ort: * The deferral of messages ensures we can print all messages about any given path together (merge-recursive was known to sometimes intersperse messages about other paths, particularly when renames were involved). * The deferral of messages means we can avoid printing spurious conflict messages when we just end up aborting due to local user modifications in the way. (In contrast to merge-recursive.c which prematurely checks for local modifications in the way via unpack_trees() and gets the check wrong both in terms of false positives and false negatives relative to renames, merge-ort does not perform the local modifications in the way check until the checkout() step after the full merge has been computed.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02ll-merge: make callers responsible for showing warningsElijah Newren
Since some callers may want to send warning messages to somewhere other than stdout/stderr, stop printing "warning: Cannot merge binary files" from ll-merge and instead modify the return status of ll_merge() to indicate when a merge of binary files has occurred. Message printing probably does not belong in a "low-level merge" anyway. This commit continues printing the message as-is, just from the callers instead of within ll_merge(). Future changes will start handling the message differently in the merge-ort codepath. There was one special case here: the callers in rerere.c do NOT check for and print such a message; since those code paths explicitly skip over binary files, there is no reason to check for a return status of LL_MERGE_BINARY_CONFLICT or print the related message. Note that my methodology included first modifying ll_merge() to return a struct, so that the compiler would catch all the callers for me and ensure I had modified all of them. After modifying all of them, I then changed the struct to an enum. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-21merge-ort: fix memory leak in merge_ort_internal()Elijah Newren
The documentation for merge_incore_recursive(), modelled after merge_recursive(), notes that merge_bases will be consumed (emptied) so make a copy if you need it However, in merge_ort_internal() (which merge_incore_recursive() calls), it runs merged_merge_bases = pop_commit(&merge_bases); ... for (iter = merge_bases; iter; iter = iter->next) { ... } In other words, it only consumes the *first* entry of merge_bases, and the rest it iterates through. If it iterated through all of them, the caller could be responsible for free'ing the memory. If it consumed all of them, the current documentation would be correct and the callers would need to do nothing. The current middle ground makes it impossible for callers to avoid memory leaks, since any attempt to use the merge_bases it passes in would result in a use-after-free. It turns out this part of the code was copied from merge-recursive.c, which has had the same bug for 15.5 years. However, since we are trying to keep merge-recursive.c stable as we sunset it, let's just fix the leak in in merge_ort_internal() by having it actually consume all the elements of the merge_bases commit_list. Testing this commit against t6404 (the first testcase specifically about recursive merges) under valgrind shows that this patch fixes the following leak: 32 (16 direct, 16 indirect) bytes in 1 blocks are definitely lost \ in loss record 49 of 126 at 0x484086F: malloc (vg_replace_malloc.c:380) by 0x69FFEB: do_xmalloc (wrapper.c:41) by 0x6A0073: xmalloc (wrapper.c:62) by 0x52A72D: commit_list_insert (commit.c:556) by 0x47EC86: try_merge_strategy (merge.c:751) by 0x48143B: cmd_merge (merge.c:1679) by 0x40686E: run_builtin (git.c:464) by 0x406C51: handle_builtin (git.c:716) by 0x406E96: run_argv (git.c:783) by 0x40730A: cmd_main (git.c:914) by 0x4E7DFA: main (common-main.c:56) Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-17merge-ort: avoid assuming all renames detectedElijah Newren
In commit 8b09a900a1 ("merge-ort: restart merge with cached renames to reduce process entry cost", 2021-07-16), we noted that in the merge-ort steps of collect_merge_info() detect_and_process_renames() process_entries() that process_entries() was expensive, and we could often make it cheaper by changing this to collect_merge_info() detect_and_process_renames() <cache all the renames, and restart> collect_merge_info() detect_and_process_renames() process_entries() because the second collect_merge_info() would be cheaper (we could avoid traversing into some directories), the second detect_and_process_renames() would be free since we had already detected all renames, and then process_entries() has far fewer entries to handle. However, this was built on the assumption that the first detect_and_process_renames() actually detected all potential renames. If someone has merge.renameLimit set to some small value, that assumption is violated which manifests later with the following message: $ git -c merge.renameLimit=1 rebase upstream ... git: merge-ort.c:546: clear_or_reinit_internal_opts: Assertion `renames->cached_pairs_valid_side == 0' failed. Turn off this cache-renames-and-restart whenever we cannot detect all renames, and add a testcase that would have caught this problem. Reported-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Elijah Newren <newren@gmail.com> Tested-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-30merge-ort: fix bug with renormalization and rename/delete conflictsElijah Newren
Ever since commit a492d5331c ("merge-ort: ensure we consult df_conflict and path_conflicts", 2021-06-30), when renormalization is active AND a file is involved in a rename/delete conflict BUT the file is unmodified (either before or after renormalization), merge-ort was running into an assertion failure. Prior to that commit (or if assertions were compiled out), merge-ort would mis-merge instead, ignoring the rename/delete conflict and just deleting the file. Remove the assertions, fix the code appropriately, leave some good comments in the code, and add a testcase for this situation. Reported-by: Ralf Thielow <ralf.thielow@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>