reset: update cache-tree data when appropriate

diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index c4bedf0d1ce1252563d7f36da7d846f5943343b0..2e669c3e2570332ee50a72e06a77ad4a356ecfd6 100644 (file)
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -85,27 +85,6 @@ static long def_ff(const char *rec, long len, char *buf, long sz, void *priv)
        return -1;
 }
 
-static void xdl_find_func(xdfile_t *xf, long i, char *buf, long sz, long *ll,
-               find_func_t ff, void *ff_priv) {
-
-       /*
-        * Be quite stupid about this for now.  Find a line in the old file
-        * before the start of the hunk (and context) which starts with a
-        * plausible character.
-        */
-
-       const char *rec;
-       long len;
-
-       while (i-- > 0) {
-               len = xdl_get_rec(xf, i, &rec);
-               if ((*ll = ff(rec, len, buf, sz, ff_priv)) >= 0)
-                       return;
-       }
-       *ll = 0;
-}
-
-
 static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
                            xdemitconf_t const *xecfg) {
        xdfile_t *xdf = &xe->xdf1;
@@ -121,13 +100,40 @@ static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
        return 0;
 }
 
+struct func_line {
+       long len;
+       char buf[80];
+};
+
+static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg,
+                         struct func_line *func_line, long start, long limit)
+{
+       find_func_t ff = xecfg->find_func ? xecfg->find_func : def_ff;
+       long l, size, step = (start > limit) ? -1 : 1;
+       char *buf, dummy[1];
+
+       buf = func_line ? func_line->buf : dummy;
+       size = func_line ? sizeof(func_line->buf) : sizeof(dummy);
+
+       for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) {
+               const char *rec;
+               long reclen = xdl_get_rec(&xe->xdf1, l, &rec);
+               long len = ff(rec, reclen, buf, size, xecfg->find_func_priv);
+               if (len >= 0) {
+                       if (func_line)
+                               func_line->len = len;
+                       return l;
+               }
+       }
+       return -1;
+}
+
 int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
                  xdemitconf_t const *xecfg) {
        long s1, s2, e1, e2, lctx;
        xdchange_t *xch, *xche;
-       char funcbuf[80];
-       long funclen = 0;
-       find_func_t ff = xecfg->find_func ?  xecfg->find_func : def_ff;
+       long funclineprev = -1;
+       struct func_line func_line = { 0 };
 
        if (xecfg->flags & XDL_EMIT_COMMON)
                return xdl_emit_common(xe, xscr, ecb, xecfg);
@@ -138,6 +144,17 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
                s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
                s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
 
+               if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
+                       long fs1 = get_func_line(xe, xecfg, NULL, xch->i1, -1);
+                       if (fs1 < 0)
+                               fs1 = 0;
+                       if (fs1 < s1) {
+                               s2 -= s1 - fs1;
+                               s1 = fs1;
+                       }
+               }
+
+ again:
                lctx = xecfg->ctxlen;
                lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
                lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
@@ -145,17 +162,43 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
                e1 = xche->i1 + xche->chg1 + lctx;
                e2 = xche->i2 + xche->chg2 + lctx;
 
+               if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
+                       long fe1 = get_func_line(xe, xecfg, NULL,
+                                                xche->i1 + xche->chg1,
+                                                xe->xdf1.nrec);
+                       if (fe1 < 0)
+                               fe1 = xe->xdf1.nrec;
+                       if (fe1 > e1) {
+                               e2 += fe1 - e1;
+                               e1 = fe1;
+                       }
+
+                       /*
+                        * Overlap with next change?  Then include it
+                        * in the current hunk and start over to find
+                        * its new end.
+                        */
+                       if (xche->next) {
+                               long l = xche->next->i1;
+                               if (l <= e1 ||
+                                   get_func_line(xe, xecfg, NULL, l, e1) < 0) {
+                                       xche = xche->next;
+                                       goto again;
+                               }
+                       }
+               }
+
                /*
                 * Emit current hunk header.
                 */
 
                if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
-                       xdl_find_func(&xe->xdf1, s1, funcbuf,
-                                     sizeof(funcbuf), &funclen,
-                                     ff, xecfg->find_func_priv);
+                       get_func_line(xe, xecfg, &func_line,
+                                     s1 - 1, funclineprev);
+                       funclineprev = s1 - 1;
                }
                if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
-                                     funcbuf, funclen, ecb) < 0)
+                                     func_line.buf, func_line.len, ecb) < 0)
                        return -1;
 
                /*