bash: remove unnecessary checks for long options with argument
[gitweb.git] / xdiff / xmerge.c
index b83b3348cc3aab66b13cb565a0a0fabaef4b689b..d9737f04c220645aa762d79ff14a84855721ffda 100644 (file)
@@ -30,17 +30,32 @@ typedef struct s_xdmerge {
         * 2 = no conflict, take second.
         */
        int mode;
+       /*
+        * These point at the respective postimages.  E.g. <i1,chg1> is
+        * how side #1 wants to change the common ancestor; if there is no
+        * overlap, lines before i1 in the postimage of side #1 appear
+        * in the merge result as a region touched by neither side.
+        */
        long i1, i2;
        long chg1, chg2;
+       /*
+        * These point at the preimage; of course there is just one
+        * preimage, that is from the shared common ancestor.
+        */
+       long i0;
+       long chg0;
 } xdmerge_t;
 
 static int xdl_append_merge(xdmerge_t **merge, int mode,
-               long i1, long chg1, long i2, long chg2)
+                           long i0, long chg0,
+                           long i1, long chg1,
+                           long i2, long chg2)
 {
        xdmerge_t *m = *merge;
        if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
                if (mode != m->mode)
                        m->mode = 0;
+               m->chg0 = i0 + chg0 - m->i0;
                m->chg1 = i1 + chg1 - m->i1;
                m->chg2 = i2 + chg2 - m->i2;
        } else {
@@ -49,6 +64,8 @@ static int xdl_append_merge(xdmerge_t **merge, int mode,
                        return -1;
                m->next = NULL;
                m->mode = mode;
+               m->i0 = i0;
+               m->chg0 = chg0;
                m->i1 = i1;
                m->chg1 = chg1;
                m->i2 = i2;
@@ -91,11 +108,13 @@ static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
        return 0;
 }
 
-static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
+static int xdl_recs_copy_0(int use_orig, xdfenv_t *xe, int i, int count, int add_nl, char *dest)
 {
-       xrecord_t **recs = xe->xdf2.recs + i;
+       xrecord_t **recs;
        int size = 0;
 
+       recs = (use_orig ? xe->xdf1.recs : xe->xdf2.recs) + i;
+
        if (count < 1)
                return 0;
 
@@ -113,65 +132,109 @@ static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
        return size;
 }
 
-static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
-               xdfenv_t *xe2, const char *name2, xdmerge_t *m, char *dest)
+static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
+{
+       return xdl_recs_copy_0(0, xe, i, count, add_nl, dest);
+}
+
+static int xdl_orig_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
+{
+       return xdl_recs_copy_0(1, xe, i, count, add_nl, dest);
+}
+
+static int fill_conflict_hunk(xdfenv_t *xe1, const char *name1,
+                             xdfenv_t *xe2, const char *name2,
+                             int size, int i, int style,
+                             xdmerge_t *m, char *dest)
 {
        const int marker_size = 7;
        int marker1_size = (name1 ? strlen(name1) + 1 : 0);
        int marker2_size = (name2 ? strlen(name2) + 1 : 0);
-       int conflict_marker_size = 3 * (marker_size + 1)
-               + marker1_size + marker2_size;
-       int size, i1, j;
-
-       for (size = i1 = 0; m; m = m->next) {
-               if (m->mode == 0) {
-                       size += xdl_recs_copy(xe1, i1, m->i1 - i1, 0,
-                                       dest ? dest + size : NULL);
-                       if (dest) {
-                               for (j = 0; j < marker_size; j++)
-                                       dest[size++] = '<';
-                               if (marker1_size) {
-                                       dest[size] = ' ';
-                                       memcpy(dest + size + 1, name1,
-                                                       marker1_size - 1);
-                                       size += marker1_size;
-                               }
-                               dest[size++] = '\n';
-                       } else
-                               size += conflict_marker_size;
-                       size += xdl_recs_copy(xe1, m->i1, m->chg1, 1,
-                                       dest ? dest + size : NULL);
-                       if (dest) {
-                               for (j = 0; j < marker_size; j++)
-                                       dest[size++] = '=';
-                               dest[size++] = '\n';
-                       }
-                       size += xdl_recs_copy(xe2, m->i2, m->chg2, 1,
-                                       dest ? dest + size : NULL);
-                       if (dest) {
-                               for (j = 0; j < marker_size; j++)
-                                       dest[size++] = '>';
-                               if (marker2_size) {
-                                       dest[size] = ' ';
-                                       memcpy(dest + size + 1, name2,
-                                                       marker2_size - 1);
-                                       size += marker2_size;
-                               }
-                               dest[size++] = '\n';
-                       }
-               } else if (m->mode == 1)
-                       size += xdl_recs_copy(xe1, i1, m->i1 + m->chg1 - i1, 0,
-                                       dest ? dest + size : NULL);
+       int j;
+
+       /* Before conflicting part */
+       size += xdl_recs_copy(xe1, i, m->i1 - i, 0,
+                             dest ? dest + size : NULL);
+
+       if (!dest) {
+               size += marker_size + 1 + marker1_size;
+       } else {
+               for (j = 0; j < marker_size; j++)
+                       dest[size++] = '<';
+               if (marker1_size) {
+                       dest[size] = ' ';
+                       memcpy(dest + size + 1, name1, marker1_size - 1);
+                       size += marker1_size;
+               }
+               dest[size++] = '\n';
+       }
+
+       /* Postimage from side #1 */
+       size += xdl_recs_copy(xe1, m->i1, m->chg1, 1,
+                             dest ? dest + size : NULL);
+
+       if (style == XDL_MERGE_DIFF3) {
+               /* Shared preimage */
+               if (!dest) {
+                       size += marker_size + 1;
+               } else {
+                       for (j = 0; j < marker_size; j++)
+                               dest[size++] = '|';
+                       dest[size++] = '\n';
+               }
+               size += xdl_orig_copy(xe1, m->i0, m->chg0, 1,
+                                     dest ? dest + size : NULL);
+       }
+
+       if (!dest) {
+               size += marker_size + 1;
+       } else {
+               for (j = 0; j < marker_size; j++)
+                       dest[size++] = '=';
+               dest[size++] = '\n';
+       }
+
+       /* Postimage from side #2 */
+       size += xdl_recs_copy(xe2, m->i2, m->chg2, 1,
+                             dest ? dest + size : NULL);
+       if (!dest) {
+               size += marker_size + 1 + marker2_size;
+       } else {
+               for (j = 0; j < marker_size; j++)
+                       dest[size++] = '>';
+               if (marker2_size) {
+                       dest[size] = ' ';
+                       memcpy(dest + size + 1, name2, marker2_size - 1);
+                       size += marker2_size;
+               }
+               dest[size++] = '\n';
+       }
+       return size;
+}
+
+static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
+                                xdfenv_t *xe2, const char *name2,
+                                xdmerge_t *m, char *dest, int style)
+{
+       int size, i;
+
+       for (size = i = 0; m; m = m->next) {
+               if (m->mode == 0)
+                       size = fill_conflict_hunk(xe1, name1, xe2, name2,
+                                                 size, i, style, m, dest);
+               else if (m->mode == 1)
+                       size += xdl_recs_copy(xe1, i, m->i1 + m->chg1 - i, 0,
+                                             dest ? dest + size : NULL);
                else if (m->mode == 2)
-                       size += xdl_recs_copy(xe2, m->i2 - m->i1 + i1,
-                                       m->i1 + m->chg2 - i1, 0,
-                                       dest ? dest + size : NULL);
+                       size += xdl_recs_copy(xe2, m->i2 - m->i1 + i,
+                                             m->i1 + m->chg2 - i, 0,
+                                             dest ? dest + size : NULL);
                else
                        continue;
-               i1 = m->i1 + m->chg1;
+               i = m->i1 + m->chg1;
        }
-       size += xdl_recs_copy(xe1, i1, xe1->xdf2.nrec - i1, 0,
-                       dest ? dest + size : NULL);
+       size += xdl_recs_copy(xe1, i, xe1->xdf2.nrec - i, 0,
+                             dest ? dest + size : NULL);
        return size;
 }
 
@@ -248,18 +311,95 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
        return 0;
 }
 
+static int line_contains_alnum(const char *ptr, long size)
+{
+       while (size--)
+               if (isalnum(*(ptr++)))
+                       return 1;
+       return 0;
+}
+
+static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
+{
+       for (; chg; chg--, i++)
+               if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
+                               xe->xdf2.recs[i]->size))
+                       return 1;
+       return 0;
+}
+
+/*
+ * This function merges m and m->next, marking everything between those hunks
+ * as conflicting, too.
+ */
+static void xdl_merge_two_conflicts(xdmerge_t *m)
+{
+       xdmerge_t *next_m = m->next;
+       m->chg1 = next_m->i1 + next_m->chg1 - m->i1;
+       m->chg2 = next_m->i2 + next_m->chg2 - m->i2;
+       m->next = next_m->next;
+       free(next_m);
+}
+
+/*
+ * If there are less than 3 non-conflicting lines between conflicts,
+ * it appears simpler -- because it takes up less (or as many) lines --
+ * if the lines are moved into the conflicts.
+ */
+static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
+                                     int simplify_if_no_alnum)
+{
+       int result = 0;
+
+       if (!m)
+               return result;
+       for (;;) {
+               xdmerge_t *next_m = m->next;
+               int begin, end;
+
+               if (!next_m)
+                       return result;
+
+               begin = m->i1 + m->chg1;
+               end = next_m->i1;
+
+               if (m->mode != 0 || next_m->mode != 0 ||
+                   (end - begin > 3 &&
+                    (!simplify_if_no_alnum ||
+                     lines_contain_alnum(xe1, begin, end - begin)))) {
+                       m = next_m;
+               } else {
+                       result++;
+                       xdl_merge_two_conflicts(m);
+               }
+       }
+}
+
 /*
  * level == 0: mark all overlapping changes as conflict
  * level == 1: mark overlapping changes as conflict only if not identical
  * level == 2: analyze non-identical changes for minimal conflict set
+ * level == 3: analyze non-identical changes for minimal conflict set, but
+ *             treat hunks not containing any letter or number as conflicting
  *
  * returns < 0 on error, == 0 for no conflicts, else number of conflicts
  */
 static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
                xdfenv_t *xe2, xdchange_t *xscr2, const char *name2,
-               int level, xpparam_t const *xpp, mmbuffer_t *result) {
+               int flags, xpparam_t const *xpp, mmbuffer_t *result) {
        xdmerge_t *changes, *c;
-       int i1, i2, chg1, chg2;
+       int i0, i1, i2, chg0, chg1, chg2;
+       int level = flags & XDL_MERGE_LEVEL_MASK;
+       int style = flags & XDL_MERGE_STYLE_MASK;
+
+       if (style == XDL_MERGE_DIFF3) {
+               /*
+                * "diff3 -m" output does not make sense for anything
+                * more aggressive than XDL_MERGE_EAGER.
+                */
+               if (XDL_MERGE_EAGER < level)
+                       level = XDL_MERGE_EAGER;
+       }
 
        c = changes = NULL;
 
@@ -267,11 +407,14 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
                if (!changes)
                        changes = c;
                if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
+                       i0 = xscr1->i1;
                        i1 = xscr1->i2;
                        i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
+                       chg0 = xscr1->chg1;
                        chg1 = xscr1->chg2;
                        chg2 = xscr1->chg1;
-                       if (xdl_append_merge(&c, 1, i1, chg1, i2, chg2)) {
+                       if (xdl_append_merge(&c, 1,
+                                            i0, chg0, i1, chg1, i2, chg2)) {
                                xdl_cleanup_merge(changes);
                                return -1;
                        }
@@ -279,18 +422,21 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
                        continue;
                }
                if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
+                       i0 = xscr2->i1;
                        i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
                        i2 = xscr2->i2;
+                       chg0 = xscr2->chg1;
                        chg1 = xscr2->chg1;
                        chg2 = xscr2->chg2;
-                       if (xdl_append_merge(&c, 2, i1, chg1, i2, chg2)) {
+                       if (xdl_append_merge(&c, 2,
+                                            i0, chg0, i1, chg1, i2, chg2)) {
                                xdl_cleanup_merge(changes);
                                return -1;
                        }
                        xscr2 = xscr2->next;
                        continue;
                }
-               if (level < 1 || xscr1->i1 != xscr2->i1 ||
+               if (level == XDL_MERGE_MINIMAL || xscr1->i1 != xscr2->i1 ||
                                xscr1->chg1 != xscr2->chg1 ||
                                xscr1->chg2 != xscr2->chg2 ||
                                xdl_merge_cmp_lines(xe1, xscr1->i2,
@@ -300,19 +446,25 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
                        int off = xscr1->i1 - xscr2->i1;
                        int ffo = off + xscr1->chg1 - xscr2->chg1;
 
+                       i0 = xscr1->i1;
                        i1 = xscr1->i2;
                        i2 = xscr2->i2;
-                       if (off > 0)
+                       if (off > 0) {
+                               i0 -= off;
                                i1 -= off;
+                       }
                        else
                                i2 += off;
+                       chg0 = xscr1->i1 + xscr1->chg1 - i0;
                        chg1 = xscr1->i2 + xscr1->chg2 - i1;
                        chg2 = xscr2->i2 + xscr2->chg2 - i2;
-                       if (ffo > 0)
-                               chg2 += ffo;
-                       else
+                       if (ffo < 0) {
+                               chg0 -= ffo;
                                chg1 -= ffo;
-                       if (xdl_append_merge(&c, 0, i1, chg1, i2, chg2)) {
+                       } else
+                               chg2 += ffo;
+                       if (xdl_append_merge(&c, 0,
+                                            i0, chg0, i1, chg1, i2, chg2)) {
                                xdl_cleanup_merge(changes);
                                return -1;
                        }
@@ -329,11 +481,14 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
        while (xscr1) {
                if (!changes)
                        changes = c;
+               i0 = xscr1->i1;
                i1 = xscr1->i2;
                i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
+               chg0 = xscr1->chg1;
                chg1 = xscr1->chg2;
                chg2 = xscr1->chg1;
-               if (xdl_append_merge(&c, 1, i1, chg1, i2, chg2)) {
+               if (xdl_append_merge(&c, 1,
+                                    i0, chg0, i1, chg1, i2, chg2)) {
                        xdl_cleanup_merge(changes);
                        return -1;
                }
@@ -342,11 +497,14 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
        while (xscr2) {
                if (!changes)
                        changes = c;
+               i0 = xscr2->i1;
                i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
                i2 = xscr2->i2;
+               chg0 = xscr2->chg1;
                chg1 = xscr2->chg1;
                chg2 = xscr2->chg2;
-               if (xdl_append_merge(&c, 2, i1, chg1, i2, chg2)) {
+               if (xdl_append_merge(&c, 2,
+                                    i0, chg0, i1, chg1, i2, chg2)) {
                        xdl_cleanup_merge(changes);
                        return -1;
                }
@@ -355,14 +513,17 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
        if (!changes)
                changes = c;
        /* refine conflicts */
-       if (level > 1 && xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0) {
+       if (XDL_MERGE_ZEALOUS <= level &&
+           (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
+            xdl_simplify_non_conflicts(xe1, changes,
+                                       XDL_MERGE_ZEALOUS < level) < 0)) {
                xdl_cleanup_merge(changes);
                return -1;
        }
        /* output */
        if (result) {
                int size = xdl_fill_merge_buffer(xe1, name1, xe2, name2,
-                       changes, NULL);
+                       changes, NULL, style);
                result->ptr = xdl_malloc(size);
                if (!result->ptr) {
                        xdl_cleanup_merge(changes);
@@ -370,14 +531,14 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
                }
                result->size = size;
                xdl_fill_merge_buffer(xe1, name1, xe2, name2, changes,
-                               result->ptr);
+                                     result->ptr, style);
        }
        return xdl_cleanup_merge(changes);
 }
 
 int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
                mmfile_t *mf2, const char *name2,
-               xpparam_t const *xpp, int level, mmbuffer_t *result) {
+               xpparam_t const *xpp, int flags, mmbuffer_t *result) {
        xdchange_t *xscr1, *xscr2;
        xdfenv_t xe1, xe2;
        int status;
@@ -414,7 +575,7 @@ int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
                } else {
                        status = xdl_do_merge(&xe1, xscr1, name1,
                                              &xe2, xscr2, name2,
-                                             level, xpp, result);
+                                             flags, xpp, result);
                }
                xdl_free_script(xscr1);
                xdl_free_script(xscr2);