merge: factor out is_cutpoint.

We perform the same test several times, so make a function for it.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/merge2.c b/merge2.c
index 3b4a96bc754053501036b842d369f3df94b8f685..2bbb709d1275fef3f959e6e1e1526aff69aeff25 100644 (file)
--- a/merge2.c
+++ b/merge2.c
@@ -79,6 +79,22 @@ static int check_alreadyapplied(struct file af, struct file cf,
        return 1;
 }
 
+/* A 'cut-point' is a location in the merger where it is reasonable
+ * the change the mode of display - between displaying the merger
+ * and displaying the separate streams.
+ * A 'conflict' can only be displayed as separate stream so when
+ * one is found, we need to find a preceeding and trailing cut-point
+ * and enlarge the conflict to that range.
+ * A suitable location is one where all three streams are at a line-end.
+ */
+static int is_cutpoint(struct merge m,
+                      struct file af, struct file bf, struct file cf)
+{
+       return ((m.a == 0 || ends_line(af.list[m.a-1])) &&
+               (m.b == 0 || ends_line(bf.list[m.b-1])) &&
+               (m.c == 0 || ends_line(cf.list[m.c-1])));
+}
+
 static int isolate_conflicts(struct file af, struct file bf, struct file cf,
                             struct csl *csl1, struct csl *csl2, int words,
                             struct merge *m, int show_wiggles)
@@ -160,18 +176,15 @@ static int isolate_conflicts(struct file af, struct file bf, struct file cf,
                                                        break;
                                        if (k > 0)
                                                m[j].hi = k;
-                                       else if ((m[j].a == 0 || ends_line(af.list[m[j].a-1])) &&
-                                                (m[j].b == 0 || ends_line(bf.list[m[j].b-1])) &&
-                                                (m[j].c == 0 || ends_line(cf.list[m[j].c-1])))
+                                       else if (is_cutpoint(m[j], af,bf,cf))
                                                m[j].hi = 0;
                                        else
                                                /* no start-of-line found... */
                                                m[j].hi = -1;
                                        if (m[j].hi > 0 && m[j].type == Changed) {
-                                               /* this can only work if start is also a line break */
-                                               if ((m[j].a == 0 || ends_line(af.list[m[j].a-1])) &&
-                                                   (m[j].b == 0 || ends_line(bf.list[m[j].b-1])) &&
-                                                   (m[j].c == 0 || ends_line(cf.list[m[j].c-1])))
+                                               /* this can only work if start is
+                                                * also a line break */
+                                               if (is_cutpoint(m[j], af,bf,cf))
                                                        /* ok */;
                                                else
                                                        m[j].hi = -1;
@@ -198,9 +211,7 @@ static int isolate_conflicts(struct file af, struct file bf, struct file cf,
                                         * the very beginning, or might be after the
                                         * first newline - if there is one
                                         */
-                                       if ((m[j].a == 0 || ends_line(af.list[m[j].a-1])) &&
-                                           (m[j].b == 0 || ends_line(bf.list[m[j].b-1])) &&
-                                           (m[j].c == 0 || ends_line(cf.list[m[j].c-1])))
+                                       if (is_cutpoint(m[j], af,bf,cf))
                                                m[j].lo = 0;
                                        else {
                                                for (k = 0 ; k < m[j].al ; k++)
@@ -214,9 +225,7 @@ static int isolate_conflicts(struct file af, struct file bf, struct file cf,
                                        }
                                        if (m[j].lo <= m[j].al+1 && m[j].type == Changed) {
                                                /* this can only work if the end is a line break */
-                                               if (ends_line(af.list[m[j].a+m[j].al-1]) &&
-                                                   ends_line(bf.list[m[j].b+m[j].bl-1]) &&
-                                                   ends_line(cf.list[m[j].c+m[j].cl-1]))
+                                               if (is_cutpoint(m[j+1], af,bf,cf))
                                                        /* ok */;
                                                else
                                                        m[j].lo = m[j].al+1;