[PATCH v2 0/5] Xdiff cleanup part 3
- From
Ezekiel Newren via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Mar 25, 2026, 21:11 UTC
- Message-ID
- <pull.2156.v2.git.git.1774473065.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.2156.git.git.1767379944.gitgitgadget@gmail.com>
v2 is a radical departure from v1 Changes in v2:
* make the flow of xdl_cleanup_records() easier to follow
There is no performance or behavioral change introduced in this patch series.
=== original cover letter bellow ===
Patch series summary:
* patch 1: Introduce the ivec type * patch 2: Create the function xdl_do_classic_diff() * patches 3-4: generic cleanup * patches 5-8: convert from dstart/dend (in xdfile_t) to delta_start/delta_end (in xdfenv_t) * patches 9-10: move xdl_cleanup_records(), and related, from xprepare.c to xdiffi.c
Things that will be addressed in future patch series:
* Make xdl_cleanup_records() easier to read * convert recs/nrec into an ivec * convert changed to an ivec * remove reference_index/nreff from xdfile_t and turn it into an ivec * splitting minimal_perfect_hash out as its own ivec * improve the performance of the classifier and parsing/hashing lines
=== before this patch series typedef struct s_xdfile { xrecord_t *recs; size_t nrec; ptrdiff_t dstart, dend; bool *changed; size_t *reference_index; size_t nreff; } xdfile_t;
typedef struct s_xdfenv { xdfile_t xdf1, xdf2; } xdfenv_t;=== after this patch series typedef struct s_xdfile { xrecord_t *recs; size_t nrec; bool *changed; size_t *reference_index; size_t nreff; } xdfile_t;
typedef struct s_xdfenv { xdfile_t xdf1, xdf2; size_t delta_start, delta_end; size_t mph_size; } xdfenv_t;
Ezekiel Newren (5): xdiff/xdl_cleanup_records: delete local recs pointer xdiff/xdl_cleanup_records: make limits more clear xdiff/xdl_cleanup_records: make setting action easier to follow xdiff/xdl_cleanup_records: simplify INVESTIGATE handling for clarity xdiff/xdl_cleanup_records: use unambiguous types
xdiff/xprepare.c | 89 ++++++++++++++++++++++++++++++++---------------- 1 file changed, 59 insertions(+), 30 deletions(-)
base-commit: ca1db8a0f7dc0dbea892e99f5b37c5fe5861be71 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2156%2Fezekielnewren%2Fxdiff-cleanup-3-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2156/ezekielnewren/xdiff-cleanup-3-v2 Pull-Request: https://github.com/git/git/pull/2156
Range-diff vs v1:
1: adf1395d20 < -: ---------- ivec: introduce the C side of ivec
2: 9bd01bce9f < -: ---------- xdiff: make classic diff explicit by creating xdl_do_classic_diff()
3: 53e4840c16 < -: ---------- xdiff: don't waste time guessing the number of lines
4: 70040ea135 < -: ---------- xdiff: let patience and histogram benefit from xdl_trim_ends()
5: 742f2d381a ! 1: 8f9165d477 xdiff: use xdfenv_t in xdl_trim_ends() and xdl_cleanup_records()
@@ Metadata
Author: Ezekiel Newren <ezekielnewren@gmail.com>
## Commit message ##
- xdiff: use xdfenv_t in xdl_trim_ends() and xdl_cleanup_records()
+ xdiff/xdl_cleanup_records: delete local recs pointer
- View with --color-words. Prepare these functions to use the fields:
- delta_start, delta_end. A future patch will add these fields to
- xdfenv_t.
+ Simplify the first 2 for loops by directly indexing the xdfile.recs.
+ recs is unused in the last 2 for loops, remove it. Best viewed with
+ --color-words.
Signed-off-by: Ezekiel Newren <ezekielnewren@gmail.com>
## xdiff/xprepare.c ##
@@ xdiff/xprepare.c: static bool xdl_clean_mmatch(uint8_t const *action, long i, long s, long e) {
- * matches on the other file. Also, lines that have multiple matches
- * might be potentially discarded if they appear in a run of discardable.
*/
--static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
-+static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) {
+ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
long i, nm, mlim;
- xrecord_t *recs;
+- xrecord_t *recs;
xdlclass_t *rcrec;
+ uint8_t *action1 = NULL, *action2 = NULL;
+ bool need_min = !!(cf->flags & XDF_NEED_MINIMAL);
@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
- * Create temporary arrays that will help us decide if
- * changed[i] should remain false, or become true.
*/
-- if (!XDL_CALLOC_ARRAY(action1, xdf1->nrec + 1)) {
-+ if (!XDL_CALLOC_ARRAY(action1, xe->xdf1.nrec + 1)) {
- ret = -1;
- goto cleanup;
- }
-- if (!XDL_CALLOC_ARRAY(action2, xdf2->nrec + 1)) {
-+ if (!XDL_CALLOC_ARRAY(action2, xe->xdf2.nrec + 1)) {
- ret = -1;
- goto cleanup;
- }
-@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
- /*
- * Initialize temporary arrays with DISCARD, KEEP, or INVESTIGATE.
- */
-- if ((mlim = xdl_bogosqrt((long)xdf1->nrec)) > XDL_MAX_EQLIMIT)
-+ if ((mlim = xdl_bogosqrt((long)xe->xdf1.nrec)) > XDL_MAX_EQLIMIT)
+ if ((mlim = xdl_bogosqrt((long)xdf1->nrec)) > XDL_MAX_EQLIMIT)
mlim = XDL_MAX_EQLIMIT;
- for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) {
-+ for (i = xe->xdf1.dstart, recs = &xe->xdf1.recs[xe->xdf1.dstart]; i <= xe->xdf1.dend; i++, recs++) {
- rcrec = cf->rcrecs[recs->minimal_perfect_hash];
+- rcrec = cf->rcrecs[recs->minimal_perfect_hash];
++ for (i = xdf1->dstart; i <= xdf1->dend; i++) {
++ size_t mph1 = xdf1->recs[i].minimal_perfect_hash;
++ rcrec = cf->rcrecs[mph1];
nm = rcrec ? rcrec->len2 : 0;
action1[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
}
-- if ((mlim = xdl_bogosqrt((long)xdf2->nrec)) > XDL_MAX_EQLIMIT)
-+ if ((mlim = xdl_bogosqrt((long)xe->xdf2.nrec)) > XDL_MAX_EQLIMIT)
+ if ((mlim = xdl_bogosqrt((long)xdf2->nrec)) > XDL_MAX_EQLIMIT)
mlim = XDL_MAX_EQLIMIT;
- for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) {
-+ for (i = xe->xdf2.dstart, recs = &xe->xdf2.recs[xe->xdf2.dstart]; i <= xe->xdf2.dend; i++, recs++) {
- rcrec = cf->rcrecs[recs->minimal_perfect_hash];
+- rcrec = cf->rcrecs[recs->minimal_perfect_hash];
++ for (i = xdf2->dstart; i <= xdf2->dend; i++) {
++ size_t mph2 = xdf2->recs[i].minimal_perfect_hash;
++ rcrec = cf->rcrecs[mph2];
nm = rcrec ? rcrec->len1 : 0;
action2[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
+ }
@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
- * Use temporary arrays to decide if changed[i] should remain
* false, or become true.
*/
-- xdf1->nreff = 0;
+ xdf1->nreff = 0;
- for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart];
- i <= xdf1->dend; i++, recs++) {
-+ xe->xdf1.nreff = 0;
-+ for (i = xe->xdf1.dstart, recs = &xe->xdf1.recs[xe->xdf1.dstart];
-+ i <= xe->xdf1.dend; i++, recs++) {
++ for (i = xdf1->dstart; i <= xdf1->dend; i++) {
if (action1[i] == KEEP ||
-- (action1[i] == INVESTIGATE && !xdl_clean_mmatch(action1, i, xdf1->dstart, xdf1->dend))) {
-- xdf1->reference_index[xdf1->nreff++] = i;
-+ (action1[i] == INVESTIGATE && !xdl_clean_mmatch(action1, i, xe->xdf1.dstart, xe->xdf1.dend))) {
-+ xe->xdf1.reference_index[xe->xdf1.nreff++] = i;
- /* changed[i] remains false, i.e. keep */
- } else
-- xdf1->changed[i] = true;
-+ xe->xdf1.changed[i] = true;
- /* i.e. discard */
+ (action1[i] == INVESTIGATE && !xdl_clean_mmatch(action1, i, xdf1->dstart, xdf1->dend))) {
+ xdf1->reference_index[xdf1->nreff++] = i;
+@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
}
-- xdf2->nreff = 0;
+ xdf2->nreff = 0;
- for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart];
- i <= xdf2->dend; i++, recs++) {
-+ xe->xdf2.nreff = 0;
-+ for (i = xe->xdf2.dstart, recs = &xe->xdf2.recs[xe->xdf2.dstart];
-+ i <= xe->xdf2.dend; i++, recs++) {
++ for (i = xdf2->dstart; i <= xdf2->dend; i++) {
if (action2[i] == KEEP ||
-- (action2[i] == INVESTIGATE && !xdl_clean_mmatch(action2, i, xdf2->dstart, xdf2->dend))) {
-- xdf2->reference_index[xdf2->nreff++] = i;
-+ (action2[i] == INVESTIGATE && !xdl_clean_mmatch(action2, i, xe->xdf2.dstart, xe->xdf2.dend))) {
-+ xe->xdf2.reference_index[xe->xdf2.nreff++] = i;
- /* changed[i] remains false, i.e. keep */
- } else
-- xdf2->changed[i] = true;
-+ xe->xdf2.changed[i] = true;
- /* i.e. discard */
- }
-
-@@ xdiff/xprepare.c: cleanup:
- /*
- * Early trim initial and terminal matching records.
- */
--static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2) {
-+static int xdl_trim_ends(xdfenv_t *xe) {
- long i, lim;
- xrecord_t *recs1, *recs2;
-
-- recs1 = xdf1->recs;
-- recs2 = xdf2->recs;
-- for (i = 0, lim = (long)XDL_MIN(xdf1->nrec, xdf2->nrec); i < lim;
-+ recs1 = xe->xdf1.recs;
-+ recs2 = xe->xdf2.recs;
-+ for (i = 0, lim = (long)XDL_MIN(xe->xdf1.nrec, xe->xdf2.nrec); i < lim;
- i++, recs1++, recs2++)
- if (recs1->minimal_perfect_hash != recs2->minimal_perfect_hash)
- break;
-
-- xdf1->dstart = xdf2->dstart = i;
-+ xe->xdf1.dstart = xe->xdf2.dstart = i;
-
-- recs1 = xdf1->recs + xdf1->nrec - 1;
-- recs2 = xdf2->recs + xdf2->nrec - 1;
-+ recs1 = xe->xdf1.recs + xe->xdf1.nrec - 1;
-+ recs2 = xe->xdf2.recs + xe->xdf2.nrec - 1;
- for (lim -= i, i = 0; i < lim; i++, recs1--, recs2--)
- if (recs1->minimal_perfect_hash != recs2->minimal_perfect_hash)
- break;
-
-- xdf1->dend = (long)xdf1->nrec - i - 1;
-- xdf2->dend = (long)xdf2->nrec - i - 1;
-+ xe->xdf1.dend = (long)xe->xdf1.nrec - i - 1;
-+ xe->xdf2.dend = (long)xe->xdf2.nrec - i - 1;
-
- return 0;
- }
-@@ xdiff/xprepare.c: int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
- xdl_classify_record(2, &cf, rec);
- }
-
-- xdl_trim_ends(&xe->xdf1, &xe->xdf2);
-+ xdl_trim_ends(xe);
- if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
- (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) &&
-- xdl_cleanup_records(&cf, &xe->xdf1, &xe->xdf2) < 0) {
-+ xdl_cleanup_records(&cf, xe) < 0) {
-
- xdl_free_ctx(&xe->xdf2);
- xdl_free_ctx(&xe->xdf1);
+ (action2[i] == INVESTIGATE && !xdl_clean_mmatch(action2, i, xdf2->dstart, xdf2->dend))) {
+ xdf2->reference_index[xdf2->nreff++] = i;
6: 65da408da9 < -: ---------- xdiff: cleanup xdl_trim_ends()
7: d74722538b < -: ---------- xdiff: replace xdfile_t.dstart with xdfenv_t.delta_start
8: d0ef5b23c4 < -: ---------- xdiff: replace xdfile_t.dend with xdfenv_t.delta_end
9: f9b10e71d2 ! 2: 62adaa8e5a xdiff: remove dependence on xdlclassifier from xdl_cleanup_records()
@@ Metadata
Author: Ezekiel Newren <ezekielnewren@gmail.com>
## Commit message ##
- xdiff: remove dependence on xdlclassifier from xdl_cleanup_records()
+ xdiff/xdl_cleanup_records: make limits more clear
- Disentangle xdl_cleanup_records() from the classifier so that it can be
- moved from xprepare.c into xdiffi.c.
-
- The classic diff is the only algorithm that needs to count the number
- of times each line occurs in each file. Make xdl_cleanup_records()
- count the number of lines instead of the classifier so it won't slow
- down patience or histogram.
+ Make the handling of per-file limits and the minimal-case clearer.
+ * Use explicit per-file limit variables (mlim1, mlim2) and initialize
+ them.
+ * The additional condition `!need_min` is redudant now, remove it.
+ Best viewed with --color-words.
Signed-off-by: Ezekiel Newren <ezekielnewren@gmail.com>
## xdiff/xprepare.c ##
-@@
- */
-
- #include "xinclude.h"
-+#include "compat/ivec.h"
-
-
- #define XDL_KPDIS_RUN 4
-@@ xdiff/xprepare.c: typedef struct s_xdlclass {
- struct s_xdlclass *next;
- xrecord_t rec;
- long idx;
-- long len1, len2;
- } xdlclass_t;
-
- typedef struct s_xdlclassifier {
-@@ xdiff/xprepare.c: static void xdl_free_classifier(xdlclassifier_t *cf) {
- }
-
-
--static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t *rec) {
-+static int xdl_classify_record(xdlclassifier_t *cf, xrecord_t *rec) {
- size_t hi;
- xdlclass_t *rcrec;
-
-@@ xdiff/xprepare.c: static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t
- return -1;
- cf->rcrecs[rcrec->idx] = rcrec;
- rcrec->rec = *rec;
-- rcrec->len1 = rcrec->len2 = 0;
- rcrec->next = cf->rchash[hi];
- cf->rchash[hi] = rcrec;
- }
-
-- (pass == 1) ? rcrec->len1++ : rcrec->len2++;
--
- rec->minimal_perfect_hash = (size_t)rcrec->idx;
-
- return 0;
@@ xdiff/xprepare.c: static bool xdl_clean_mmatch(uint8_t const *action, long i, long s, long e) {
- return rpdis1 * XDL_KPDIS_RUN < (rpdis1 + rdis1);
- }
-
-+struct xoccurrence
-+{
-+ size_t file1, file2;
-+};
-+
-+
-+DEFINE_IVEC_TYPE(struct xoccurrence, xoccurrence);
-+
-
- /*
- * Try to reduce the problem complexity, discard records that have no
- * matches on the other file. Also, lines that have multiple matches
* might be potentially discarded if they appear in a run of discardable.
*/
--static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) {
+ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
- long i, nm, mlim;
-+static int xdl_cleanup_records(xdfenv_t *xe, uint64_t flags) {
-+ long i;
-+ size_t nm, mlim;
- xrecord_t *recs;
-- xdlclass_t *rcrec;
++ long i, nm;
++ size_t mlim1, mlim2;
+ xdlclass_t *rcrec;
uint8_t *action1 = NULL, *action2 = NULL;
-- bool need_min = !!(cf->flags & XDF_NEED_MINIMAL);
-+ struct IVec_xoccurrence occ;
-+ bool need_min = !!(flags & XDF_NEED_MINIMAL);
- int ret = 0;
- ptrdiff_t dend1 = xe->xdf1.nrec - 1 - xe->delta_end;
- ptrdiff_t dend2 = xe->xdf2.nrec - 1 - xe->delta_end;
+ bool need_min = !!(cf->flags & XDF_NEED_MINIMAL);
+@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
+ goto cleanup;
+ }
-+ IVEC_INIT(occ);
-+ ivec_zero(&occ, xe->mph_size);
-+
-+ for (size_t j = 0; j < xe->xdf1.nrec; j++) {
-+ size_t mph1 = xe->xdf1.recs[j].minimal_perfect_hash;
-+ occ.ptr[mph1].file1 += 1;
-+ }
-+
-+ for (size_t j = 0; j < xe->xdf2.nrec; j++) {
-+ size_t mph2 = xe->xdf2.recs[j].minimal_perfect_hash;
-+ occ.ptr[mph2].file2 += 1;
++ if (need_min) {
++ /* i.e. infinity */
++ mlim1 = SIZE_MAX;
++ mlim2 = SIZE_MAX;
++ } else {
++ mlim1 = XDL_MIN(xdl_bogosqrt(xdf1->nrec), XDL_MAX_EQLIMIT);
++ mlim2 = XDL_MIN(xdl_bogosqrt(xdf2->nrec), XDL_MAX_EQLIMIT);
+ }
+
/*
- * Create temporary arrays that will help us decide if
- * changed[i] should remain false, or become true.
-@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) {
- if ((mlim = xdl_bogosqrt((long)xe->xdf1.nrec)) > XDL_MAX_EQLIMIT)
- mlim = XDL_MAX_EQLIMIT;
- for (i = xe->delta_start, recs = &xe->xdf1.recs[xe->delta_start]; i <= dend1; i++, recs++) {
-- rcrec = cf->rcrecs[recs->minimal_perfect_hash];
-- nm = rcrec ? rcrec->len2 : 0;
-+ nm = occ.ptr[recs->minimal_perfect_hash].file2;
- action1[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
+ * Initialize temporary arrays with DISCARD, KEEP, or INVESTIGATE.
+ */
+- if ((mlim = xdl_bogosqrt((long)xdf1->nrec)) > XDL_MAX_EQLIMIT)
+- mlim = XDL_MAX_EQLIMIT;
+ for (i = xdf1->dstart; i <= xdf1->dend; i++) {
+ size_t mph1 = xdf1->recs[i].minimal_perfect_hash;
+ rcrec = cf->rcrecs[mph1];
+ nm = rcrec ? rcrec->len2 : 0;
+- action1[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
++ action1[i] = (nm == 0) ? DISCARD: nm >= mlim1 ? INVESTIGATE: KEEP;
}
- if ((mlim = xdl_bogosqrt((long)xe->xdf2.nrec)) > XDL_MAX_EQLIMIT)
- mlim = XDL_MAX_EQLIMIT;
- for (i = xe->delta_start, recs = &xe->xdf2.recs[xe->delta_start]; i <= dend2; i++, recs++) {
-- rcrec = cf->rcrecs[recs->minimal_perfect_hash];
-- nm = rcrec ? rcrec->len1 : 0;
-+ nm = occ.ptr[recs->minimal_perfect_hash].file1;
- action2[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
- }
-
-@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) {
- cleanup:
- xdl_free(action1);
- xdl_free(action2);
-+ ivec_free(&occ);
-
- return ret;
- }
-@@ xdiff/xprepare.c: int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
-
- for (size_t i = 0; i < xe->xdf1.nrec; i++) {
- xrecord_t *rec = &xe->xdf1.recs[i];
-- xdl_classify_record(1, &cf, rec);
-+ xdl_classify_record(&cf, rec);
+- if ((mlim = xdl_bogosqrt((long)xdf2->nrec)) > XDL_MAX_EQLIMIT)
+- mlim = XDL_MAX_EQLIMIT;
+ for (i = xdf2->dstart; i <= xdf2->dend; i++) {
+ size_t mph2 = xdf2->recs[i].minimal_perfect_hash;
+ rcrec = cf->rcrecs[mph2];
+ nm = rcrec ? rcrec->len1 : 0;
+- action2[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
++ action2[i] = (nm == 0) ? DISCARD: nm >= mlim2 ? INVESTIGATE: KEEP;
}
- for (size_t i = 0; i < xe->xdf2.nrec; i++) {
- xrecord_t *rec = &xe->xdf2.recs[i];
-- xdl_classify_record(2, &cf, rec);
-+ xdl_classify_record(&cf, rec);
- }
-
-+ xe->mph_size = cf.count;
-+
- xdl_trim_ends(xe);
- if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
- (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) &&
-- xdl_cleanup_records(&cf, xe) < 0) {
-+ xdl_cleanup_records(xe, xpp->flags) < 0) {
-
- xdl_free_ctx(&xe->xdf2);
- xdl_free_ctx(&xe->xdf1);
-
- ## xdiff/xtypes.h ##
-@@ xdiff/xtypes.h: typedef struct s_xdfile {
- typedef struct s_xdfenv {
- xdfile_t xdf1, xdf2;
- size_t delta_start, delta_end;
-+ size_t mph_size;
- } xdfenv_t;
-
-
+ /*
10: 1dba6b34aa < -: ---------- xdiff: move xdl_cleanup_records() from xprepare.c to xdiffi.c
-: ---------- > 3: 8be7e4781a xdiff/xdl_cleanup_records: make setting action easier to follow
-: ---------- > 4: 6abd052c34 xdiff/xdl_cleanup_records: simplify INVESTIGATE handling for clarity
-: ---------- > 5: a52787f019 xdiff/xdl_cleanup_records: use unambiguous types-- gitgitgadget