ui-log: Fix filecount/linecount when path limit is in effect

When using ui-log with path limits, the listing of commits enables parent
rewriting in Git's internal log machinery. This did not work well together
with cgit_diff_commit() which is used to generate the filecount and
linecount numbers for each commit in the log view. cgit_diff_commit() would
operate without any path limits, and would therefore process the full diff
between the commits shown (which, because of parent rewriting, is not the
same as processing the diff for the commit itself). Additionally, the bottom
commit in the log view would (again, because of parent rewriting) have zero
parents, causing us to process the entire diff between the empty tree and
that commit. Since path limits were not in effect, this would (in large
projects) reports thousands of files and millions of lines changed in that
bottom commit.

This patch fixes the issue by applying the same path limit to
cgit_diff_commit() as is applied to the rest of the log view. The result is
that the filecount/linecount now only reflects the diff as it pertains to
the given path limit.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

3 files changed, 5 insertions, 4 deletions

diff --git a/cgit.h b/cgit.h
index a9896cf..f5f68ac 100644
--- a/cgit.h
+++ b/cgit.h
@@ -281,33 +281,34 @@ extern char *strrpart(char *txt, int maxlen);
 extern void cgit_add_ref(struct reflist *list, struct refinfo *ref);
 extern int cgit_refs_cb(const char *refname, const unsigned char *sha1,
                         int flags, void *cb_data);
 
 extern void *cgit_free_commitinfo(struct commitinfo *info);
 
 extern int cgit_diff_files(const unsigned char *old_sha1,
                            const unsigned char *new_sha1,
                            unsigned long *old_size, unsigned long *new_size,
                            int *binary, int context, int ignorews,
                            linediff_fn fn);
 
 extern void cgit_diff_tree(const unsigned char *old_sha1,
                            const unsigned char *new_sha1,
                            filepair_fn fn, const char *prefix, int ignorews);
 
-extern void cgit_diff_commit(struct commit *commit, filepair_fn fn);
+extern void cgit_diff_commit(struct commit *commit, filepair_fn fn,
+                             const char *prefix);
 
 __attribute__((format (printf,1,2)))
 extern char *fmt(const char *format,...);
 
 extern struct commitinfo *cgit_parse_commit(struct commit *commit);
 extern struct taginfo *cgit_parse_tag(struct tag *tag);
 extern void cgit_parse_url(const char *url);
 
 extern const char *cgit_repobasename(const char *reponame);
 
 extern int cgit_parse_snapshots_mask(const char *str);
 
 extern int cgit_open_filter(struct cgit_filter *filter);
 extern int cgit_close_filter(struct cgit_filter *filter);
 
 extern int readfile(const char *path, char **buf, size_t *size);
diff --git a/shared.c b/shared.c
index 72ac140..765cd27 100644
--- a/shared.c
+++ b/shared.c
@@ -325,39 +325,39 @@ void cgit_diff_tree(const unsigned char *old_sha1,
         if (prefix) {
                 opt.nr_paths = 1;
                 opt.paths = &prefix;
                 prefixlen = strlen(prefix);
                 opt.pathlens = &prefixlen;
         }
         diff_setup_done(&opt);
 
         if (old_sha1 && !is_null_sha1(old_sha1))
                 ret = diff_tree_sha1(old_sha1, new_sha1, "", &opt);
         else
                 ret = diff_root_tree_sha1(new_sha1, "", &opt);
         diffcore_std(&opt);
         diff_flush(&opt);
 }
 
-void cgit_diff_commit(struct commit *commit, filepair_fn fn)
+void cgit_diff_commit(struct commit *commit, filepair_fn fn, const char *prefix)
 {
         unsigned char *old_sha1 = NULL;
 
         if (commit->parents)
                 old_sha1 = commit->parents->item->object.sha1;
-        cgit_diff_tree(old_sha1, commit->object.sha1, fn, NULL,
+        cgit_diff_tree(old_sha1, commit->object.sha1, fn, prefix,
                        ctx.qry.ignorews);
 }
 
 int cgit_parse_snapshots_mask(const char *str)
 {
         const struct cgit_snapshot_format *f;
         static const char *delim = " \t,:/|;";
         int tl, sl, rv = 0;
 
         /* favor legacy setting */
         if(atoi(str))
                 return 1;
         for(;;) {
                 str += strspn(str,delim);
                 tl = strcspn(str,delim);
                 if (!tl)
diff --git a/ui-log.c b/ui-log.c
index 41b5225..bc0c02c 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -88,33 +88,33 @@ void print_commit(struct commit *commit)
         tmp = fmt("id=%s", sha1_to_hex(commit->object.sha1));
         tmp = cgit_fileurl(ctx.repo->url, "commit", ctx.qry.vpath, tmp);
         html_link_open(tmp, NULL, NULL);
         cgit_print_age(commit->date, TM_WEEK * 2, FMT_SHORTDATE);
         html_link_close();
         htmlf("</td><td%s>",
                 ctx.qry.showmsg ? " class='logsubject'" : "");
         cgit_commit_link(info->subject, NULL, NULL, ctx.qry.head,
                          sha1_to_hex(commit->object.sha1), ctx.qry.vpath, 0);
         show_commit_decorations(commit);
         html("</td><td>");
         html_txt(info->author);
         if (ctx.repo->enable_log_filecount) {
                 files = 0;
                 add_lines = 0;
                 rem_lines = 0;
-                cgit_diff_commit(commit, inspect_files);
+                cgit_diff_commit(commit, inspect_files, ctx.qry.vpath);
                 html("</td><td>");
                 htmlf("%d", files);
                 if (ctx.repo->enable_log_linecount) {
                         html("</td><td>");
                         htmlf("-%d/+%d", rem_lines, add_lines);
                 }
         }
         html("</td></tr>\n");
         if (ctx.qry.showmsg) {
                 struct strbuf notes = STRBUF_INIT;
                 format_note(NULL, commit->object.sha1, &notes, PAGE_ENCODING, 0);
 
                 if (ctx.repo->enable_log_filecount) {
                         cols++;
                         if (ctx.repo->enable_log_linecount)
                                 cols++;