1 files changed, 120 insertions, 11 deletions

diff --git a/ui-log.c b/ui-log.c
index 8028b27..ff832ce 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -12,7 +12,7 @@
 #include "ui-shared.h"
 #include "argv-array.h"
 
-static int files, add_lines, rem_lines;
+static int files, add_lines, rem_lines, lines_counted;
 
 /*
  * The list of available column colors in the commit graph.
@@ -67,7 +67,7 @@ void show_commit_decorations(struct commit *commit)
                         strncpy(buf, deco->name + 11, sizeof(buf) - 1);
                         cgit_log_link(buf, NULL, "branch-deco", buf, NULL,
                                       ctx.qry.vpath, 0, NULL, NULL,
-                                      ctx.qry.showmsg);
+                                      ctx.qry.showmsg, 0);
                 }
                 else if (starts_with(deco->name, "tag: refs/tags/")) {
                         strncpy(buf, deco->name + 15, sizeof(buf) - 1);
@@ -84,7 +84,7 @@ void show_commit_decorations(struct commit *commit)
                         cgit_log_link(buf, NULL, "remote-deco", NULL,
                                       sha1_to_hex(commit->object.sha1),
                                       ctx.qry.vpath, 0, NULL, NULL,
-                                      ctx.qry.showmsg);
+                                      ctx.qry.showmsg, 0);
                 }
                 else {
                         strncpy(buf, deco->name, sizeof(buf) - 1);
@@ -98,6 +98,74 @@ next:
         html("</span>");
 }
 
+static void handle_rename(struct diff_filepair *pair)
+{
+        /*
+         * After we have seen a rename, we generate links to the previous
+         * name of the file so that commit & diff views get fed the path
+         * that is correct for the commit they are showing, avoiding the
+         * need to walk the entire history leading back to every commit we
+         * show in order detect renames.
+         */
+        if (0 != strcmp(ctx.qry.vpath, pair->two->path)) {
+                free(ctx.qry.vpath);
+                ctx.qry.vpath = xstrdup(pair->two->path);
+        }
+        inspect_files(pair);
+}
+
+static int show_commit(struct commit *commit, struct rev_info *revs)
+{
+        struct commit_list *parents = commit->parents;
+        struct commit *parent;
+        int found = 0, saved_fmt;
+        unsigned saved_flags = revs->diffopt.flags;
+
+
+        /* Always show if we're not in "follow" mode with a single file. */
+        if (!ctx.qry.follow)
+                return 1;
+
+        /*
+         * In "follow" mode, we don't show merges.  This is consistent with
+         * "git log --follow -- <file>".
+         */
+        if (parents && parents->next)
+                return 0;
+
+        /*
+         * If this is the root commit, do what rev_info tells us.
+         */
+        if (!parents)
+                return revs->show_root_diff;
+
+        /* When we get here we have precisely one parent. */
+        parent = parents->item;
+        parse_commit(parent);
+
+        files = 0;
+        add_lines = 0;
+        rem_lines = 0;
+
+        DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
+        diff_tree_sha1(parent->tree->object.sha1,
+                       commit->tree->object.sha1,
+                       "", &revs->diffopt);
+        diffcore_std(&revs->diffopt);
+
+        found = !diff_queue_is_empty();
+        saved_fmt = revs->diffopt.output_format;
+        revs->diffopt.output_format = DIFF_FORMAT_CALLBACK;
+        revs->diffopt.format_callback = cgit_diff_tree_cb;
+        revs->diffopt.format_callback_data = handle_rename;
+        diff_flush(&revs->diffopt);
+        revs->diffopt.output_format = saved_fmt;
+        revs->diffopt.flags = saved_flags;
+
+        lines_counted = 1;
+        return found;
+}
+
 static void print_commit(struct commit *commit, struct rev_info *revs)
 {
         struct commitinfo *info;
@@ -177,7 +245,8 @@ static void print_commit(struct commit *commit, struct rev_info *revs)
                 cgit_print_age(commit->date, TM_WEEK * 2, FMT_SHORTDATE);
         }
 
-        if (ctx.repo->enable_log_filecount || ctx.repo->enable_log_linecount) {
+        if (!lines_counted && (ctx.repo->enable_log_filecount ||
+                               ctx.repo->enable_log_linecount)) {
                 files = 0;
                 add_lines = 0;
                 rem_lines = 0;
@@ -325,7 +394,17 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
                         }
                 }
         }
-        if (commit_graph) {
+
+        if (!path || !ctx.cfg.enable_follow_links) {
+                /*
+                 * If we don't have a path, "follow" is a no-op so make sure
+                 * the variable is set to false to avoid needing to check
+                 * both this and whether we have a path everywhere.
+                 */
+                ctx.qry.follow = 0;
+        }
+
+        if (commit_graph && !ctx.qry.follow) {
                 argv_array_push(&rev_argv, "--graph");
                 argv_array_push(&rev_argv, "--color");
                 graph_set_column_colors(column_colors_html,
@@ -337,6 +416,8 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
         else if (commit_sort == 2)
                 argv_array_push(&rev_argv, "--topo-order");
 
+        if (path && ctx.qry.follow)
+                argv_array_push(&rev_argv, "--follow");
         argv_array_push(&rev_argv, "--");
         if (path)
                 argv_array_push(&rev_argv, path);
@@ -347,10 +428,17 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
         rev.verbose_header = 1;
         rev.show_root_diff = 0;
         rev.ignore_missing = 1;
+        rev.simplify_history = 1;
         setup_revisions(rev_argv.argc, rev_argv.argv, &rev, NULL);
         load_ref_decorations(DECORATE_FULL_REFS);
         rev.show_decorations = 1;
         rev.grep_filter.regflags |= REG_ICASE;
+
+        rev.diffopt.detect_rename = 1;
+        rev.diffopt.rename_limit = ctx.cfg.renamelimit;
+        if (ctx.qry.ignorews)
+                DIFF_XDL_SET(&rev.diffopt, IGNORE_WHITESPACE);
+
         compile_grep_patterns(&rev.grep_filter);
         prepare_revision_walk(&rev);
 
@@ -368,11 +456,12 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
                 cgit_log_link(ctx.qry.showmsg ? "Collapse" : "Expand", NULL,
                               NULL, ctx.qry.head, ctx.qry.sha1,
                               ctx.qry.vpath, ctx.qry.ofs, ctx.qry.grep,
-                              ctx.qry.search, ctx.qry.showmsg ? 0 : 1);
+                              ctx.qry.search, ctx.qry.showmsg ? 0 : 1,
+                              ctx.qry.follow);
                 html(")");
         }
         html("</th><th class='left'>Author</th>");
-        if (commit_graph)
+        if (rev.graph)
                 html("<th class='left'>Age</th>");
         if (ctx.repo->enable_log_filecount) {
                 html("<th class='left'>Files</th>");
@@ -388,13 +477,30 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
                 ofs = 0;
 
         for (i = 0; i < ofs && (commit = get_revision(&rev)) != NULL; i++) {
+                if (show_commit(commit, &rev))
+                        i++;
                 free_commit_buffer(commit);
                 free_commit_list(commit->parents);
                 commit->parents = NULL;
         }
 
         for (i = 0; i < cnt && (commit = get_revision(&rev)) != NULL; i++) {
-                print_commit(commit, &rev);
+                /*
+                 * In "follow" mode, we must count the files and lines the
+                 * first time we invoke diff on a given commit, and we need
+                 * to do that to see if the commit touches the path we care
+                 * about, so we do it in show_commit.  Hence we must clear
+                 * lines_counted here.
+                 *
+                 * This has the side effect of avoiding running diff twice
+                 * when we are both following renames and showing file
+                 * and/or line counts.
+                 */
+                lines_counted = 0;
+                if (show_commit(commit, &rev)) {
+                        i++;
+                        print_commit(commit, &rev);
+                }
                 free_commit_buffer(commit);
                 free_commit_list(commit->parents);
                 commit->parents = NULL;
@@ -406,7 +512,8 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
                         cgit_log_link("[prev]", NULL, NULL, ctx.qry.head,
                                       ctx.qry.sha1, ctx.qry.vpath,
                                       ofs - cnt, ctx.qry.grep,
-                                      ctx.qry.search, ctx.qry.showmsg);
+                                      ctx.qry.search, ctx.qry.showmsg,
+                                      ctx.qry.follow);
                         html("</li>");
                 }
                 if ((commit = get_revision(&rev)) != NULL) {
@@ -414,14 +521,16 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
                         cgit_log_link("[next]", NULL, NULL, ctx.qry.head,
                                       ctx.qry.sha1, ctx.qry.vpath,
                                       ofs + cnt, ctx.qry.grep,
-                                      ctx.qry.search, ctx.qry.showmsg);
+                                      ctx.qry.search, ctx.qry.showmsg,
+                                      ctx.qry.follow);
                         html("</li>");
                 }
                 html("</ul>");
         } else if ((commit = get_revision(&rev)) != NULL) {
                 htmlf("<tr class='nohover'><td colspan='%d'>", columns);
                 cgit_log_link("[...]", NULL, NULL, ctx.qry.head, NULL,
-                              ctx.qry.vpath, 0, NULL, NULL, ctx.qry.showmsg);
+                              ctx.qry.vpath, 0, NULL, NULL, ctx.qry.showmsg,
+                              ctx.qry.follow);
                 html("</td></tr>\n");
         }