14 files changed, 338 insertions, 63 deletions

diff --git a/Makefile b/Makefile
index fe4b10e..a988751 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ htmldir = $(docdir)
 pdfdir = $(docdir)
 mandir = $(prefix)/share/man
 SHA1_HEADER = <openssl/sha.h>
-GIT_VER = 1.7.3
+GIT_VER = 1.7.4
 GIT_URL = http://www.kernel.org/pub/software/scm/git/git-$(GIT_VER).tar.bz2
 INSTALL = install
 MAN5_TXT = $(wildcard *.5.txt)
@@ -115,6 +115,7 @@ OBJECTS += ui-stats.o
 OBJECTS += ui-summary.o
 OBJECTS += ui-tag.o
 OBJECTS += ui-tree.o
+OBJECTS += vector.o
 
 ifdef NEEDS_LIBICONV
         EXTLIBS += -liconv
diff --git a/cgit.c b/cgit.c
index 6a76281..71f3fc8 100644
--- a/cgit.c
+++ b/cgit.c
@@ -57,6 +57,8 @@ void repo_config(struct cgit_repo *repo, const char *name, const char *value)
                 repo->defbranch = xstrdup(value);
         else if (!strcmp(name, "snapshots"))
                 repo->snapshots = ctx.cfg.snapshots & cgit_parse_snapshots_mask(value);
+        else if (!strcmp(name, "enable-commit-graph"))
+                repo->enable_commit_graph = ctx.cfg.enable_commit_graph * atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 repo->enable_log_filecount = ctx.cfg.enable_log_filecount * atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
@@ -141,6 +143,8 @@ void config_cb(const char *name, const char *value)
                 ctx.cfg.enable_gitweb_owner = atoi(value);
         else if (!strcmp(name, "enable-index-links"))
                 ctx.cfg.enable_index_links = atoi(value);
+        else if (!strcmp(name, "enable-commit-graph"))
+                ctx.cfg.enable_commit_graph = atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 ctx.cfg.enable_log_filecount = atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
@@ -543,6 +547,8 @@ void print_repo(FILE *f, struct cgit_repo *repo)
                 fprintf(f, "repo.section=%s\n", repo->section);
         if (repo->clone_url)
                 fprintf(f, "repo.clone-url=%s\n", repo->clone_url);
+        fprintf(f, "repo.enable-commit-graph=%d\n",
+                repo->enable_commit_graph);
         fprintf(f, "repo.enable-log-filecount=%d\n",
                 repo->enable_log_filecount);
         fprintf(f, "repo.enable-log-linecount=%d\n",
diff --git a/cgit.css b/cgit.css
index a2a685b..008cff8 100644
--- a/cgit.css
+++ b/cgit.css
@@ -153,26 +153,44 @@ table.list td {
         padding: 0.1em 0.5em 0.1em 0.5em;
 }
 
-table.list td.logsubject {
+table.list td.commitgraph {
         font-family: monospace;
-        font-weight: bold;
+        white-space: pre;
 }
 
-table.list td.logmsg {
-        font-family: monospace;
-        white-space: pre;
-        padding: 1em 0.5em 2em 0.5em;
+table.list td.commitgraph .column1 {
+        color: #a00;
+}
+
+table.list td.commitgraph .column2 {
+        color: #0a0;
+}
+
+table.list td.commitgraph .column3 {
+        color: #aa0;
 }
 
-table.list td.lognotes-label {
-        text-align:right;
-        vertical-align:top;
+table.list td.commitgraph .column4 {
+        color: #00a;
 }
 
-table.list td.lognotes {
+table.list td.commitgraph .column5 {
+        color: #a0a;
+}
+
+table.list td.commitgraph .column6 {
+        color: #0aa;
+}
+
+table.list td.logsubject {
+        font-family: monospace;
+        font-weight: bold;
+}
+
+table.list td.logmsg {
         font-family: monospace;
         white-space: pre;
-        padding: 0em 0.5em 2em 0.5em;
+        padding: 0 0.5em;
 }
 
 table.list td a {
diff --git a/cgit.h b/cgit.h
index ad94905..74aa340 100644
--- a/cgit.h
+++ b/cgit.h
@@ -20,6 +20,7 @@
 #include <xdiff/xdiff.h>
 #include <utf8.h>
 #include <notes.h>
+#include <graph.h>
 
 
 /*
@@ -71,6 +72,7 @@ struct cgit_repo {
         char *section;
         char *clone_url;
         int snapshots;
+        int enable_commit_graph;
         int enable_log_filecount;
         int enable_log_linecount;
         int enable_remote_branches;
@@ -188,6 +190,7 @@ struct cgit_config {
         int enable_filter_overrides;
         int enable_gitweb_owner;
         int enable_index_links;
+        int enable_commit_graph;
         int enable_log_filecount;
         int enable_log_linecount;
         int enable_remote_branches;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 1dc3cce..a832830 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -90,7 +90,12 @@ embedded::
         Flag which, when set to "1", will make cgit generate a html fragment
         suitable for embedding in other html pages. Default value: none. See
         also: "noheader".
-        
+
+enable-commit-graph::
+        Flag which, when set to "1", will make cgit print an ASCII-art commit
+        history graph to the left of the commit messages in the repository
+        log page. Default value: "0".
+
 enable-filter-overrides::
         Flag which, when set to "1", allows all filter settings to be
         overridden in repository-specific cgitrc files. Default value: none.
@@ -362,6 +367,10 @@ repo.defbranch::
 repo.desc::
         The value to show as repository description. Default value: none.
 
+repo.enable-commit-graph::
+        A flag which can be used to disable the global setting
+        `enable-commit-graph'. Default value: none.
+
 repo.enable-log-filecount::
         A flag which can be used to disable the global setting
         `enable-log-filecount'. Default value: none.
@@ -449,6 +458,10 @@ css=/css/cgit.css
 enable-index-links=1
 
 
+# Enable ASCII art commit history graph on the log pages
+enable-commit-graph=1
+
+
 # Show number of affected files per commit on the log pages
 enable-log-filecount=1
 
diff --git a/cmd.c b/cmd.c
index 6dc9f5e..536515b 100644
--- a/cmd.c
+++ b/cmd.c
@@ -67,7 +67,8 @@ static void info_fn(struct cgit_context *ctx)
 static void log_fn(struct cgit_context *ctx)
 {
         cgit_print_log(ctx->qry.sha1, ctx->qry.ofs, ctx->cfg.max_commit_count,
-                       ctx->qry.grep, ctx->qry.search, ctx->qry.path, 1);
+                       ctx->qry.grep, ctx->qry.search, ctx->qry.path, 1,
+                       ctx->repo->enable_commit_graph);
 }
 
 static void ls_cache_fn(struct cgit_context *ctx)
diff --git a/git b/git
-Subproject 87b50542a08ac6caa083ddc376e674424e37940
+Subproject 7ed863a85a6ce2c4ac4476848310b8f917ab41f
diff --git a/html.c b/html.c
index 1305910..a1fe87d 100644
--- a/html.c
+++ b/html.c
@@ -18,7 +18,7 @@ static const char* url_escape_table[256] = {
         "%00", "%01", "%02", "%03", "%04", "%05", "%06", "%07", "%08", "%09",
         "%0a", "%0b", "%0c", "%0d", "%0e", "%0f", "%10", "%11", "%12", "%13",
         "%14", "%15", "%16", "%17", "%18", "%19", "%1a", "%1b", "%1c", "%1d",
-        "%1e", "%1f", "%20", 0, "%22", "%23", 0, "%25", "%26", "%27", 0, 0, 0,
+        "%1e", "%1f", "+", 0, "%22", "%23", 0, "%25", "%26", "%27", 0, 0, 0,
         "%2b", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, "%3c", "%3d",
         "%3e", "%3f", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, "%5c", 0, "%5e", 0, "%60", 0, 0, 0, 0, 0,
@@ -181,7 +181,7 @@ void html_url_arg(const char *txt)
                 const char *e = url_escape_table[c];
                 if (e) {
                         html_raw(txt, t - txt);
-                        html_raw(e, 3);
+                        html_raw(e, strlen(e));
                         txt = t+1;
                 }
                 t++;
diff --git a/shared.c b/shared.c
index 765cd27..7ec2e19 100644
--- a/shared.c
+++ b/shared.c
@@ -56,6 +56,7 @@ struct cgit_repo *cgit_add_repo(const char *url)
         ret->section = ctx.cfg.section;
         ret->defbranch = "master";
         ret->snapshots = ctx.cfg.snapshots;
+        ret->enable_commit_graph = ctx.cfg.enable_commit_graph;
         ret->enable_log_filecount = ctx.cfg.enable_log_filecount;
         ret->enable_log_linecount = ctx.cfg.enable_log_linecount;
         ret->enable_remote_branches = ctx.cfg.enable_remote_branches;
diff --git a/ui-log.c b/ui-log.c
index b9771fa..8add66a 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -9,9 +9,25 @@
 #include "cgit.h"
 #include "html.h"
 #include "ui-shared.h"
+#include "vector.h"
 
 int files, add_lines, rem_lines;
 
+/*
+ * The list of available column colors in the commit graph.
+ */
+static const char *column_colors_html[] = {
+        "<span class='column1'>",
+        "<span class='column2'>",
+        "<span class='column3'>",
+        "<span class='column4'>",
+        "<span class='column5'>",
+        "<span class='column6'>",
+        "</span>",
+};
+
+#define COLUMN_COLORS_HTML_MAX (ARRAY_SIZE(column_colors_html) - 1)
+
 void count_lines(char *line, int size)
 {
         if (size <= 0)
@@ -76,27 +92,93 @@ void show_commit_decorations(struct commit *commit)
         }
 }
 
-void print_commit(struct commit *commit)
+void print_commit(struct commit *commit, struct rev_info *revs)
 {
         struct commitinfo *info;
         char *tmp;
-        int cols = 2;
+        int cols = revs->graph ? 3 : 2;
+        struct strbuf graphbuf = STRBUF_INIT;
+        struct strbuf msgbuf = STRBUF_INIT;
+
+        if (ctx.repo->enable_log_filecount) {
+                cols++;
+                if (ctx.repo->enable_log_linecount)
+                        cols++;
+        }
+
+        if (revs->graph) {
+                /* Advance graph until current commit */
+                while (!graph_next_line(revs->graph, &graphbuf)) {
+                        /* Print graph segment in otherwise empty table row */
+                        html("<tr class='nohover'><td class='commitgraph'>");
+                        html(graphbuf.buf);
+                        htmlf("</td><td colspan='%d' /></tr>\n", cols);
+                        strbuf_setlen(&graphbuf, 0);
+                }
+                /* Current commit's graph segment is now ready in graphbuf */
+        }
 
         info = cgit_parse_commit(commit);
-        htmlf("<tr%s><td>",
-                ctx.qry.showmsg ? " class='logheader'" : "");
-        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'" : "");
+        htmlf("<tr%s>", ctx.qry.showmsg ? " class='logheader'" : "");
+
+        if (revs->graph) {
+                /* Print graph segment for current commit */
+                html("<td class='commitgraph'>");
+                html(graphbuf.buf);
+                html("</td>");
+                strbuf_setlen(&graphbuf, 0);
+        }
+        else {
+                html("<td>");
+                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();
+                html("</td>");
+        }
+
+        htmlf("<td%s>", ctx.qry.showmsg ? " class='logsubject'" : "");
+        if (ctx.qry.showmsg) {
+                /* line-wrap long commit subjects instead of truncating them */
+                size_t subject_len = strlen(info->subject);
+
+                if (subject_len > ctx.cfg.max_msg_len &&
+                    ctx.cfg.max_msg_len >= 15) {
+                        /* symbol for signaling line-wrap (in PAGE_ENCODING) */
+                        const char wrap_symbol[] = { ' ', 0xE2, 0x86, 0xB5, 0 };
+                        int i = ctx.cfg.max_msg_len - strlen(wrap_symbol);
+
+                        /* Rewind i to preceding space character */
+                        while (i > 0 && !isspace(info->subject[i]))
+                                --i;
+                        if (!i) /* Oops, zero spaces. Reset i */
+                                i = ctx.cfg.max_msg_len - strlen(wrap_symbol);
+
+                        /* add remainder starting at i to msgbuf */
+                        strbuf_add(&msgbuf, info->subject + i, subject_len - i);
+                        strbuf_trim(&msgbuf);
+                        strbuf_add(&msgbuf, "\n\n", 2);
+
+                        /* Place wrap_symbol at position i in info->subject */
+                        strcpy(info->subject + i, wrap_symbol);
+                }
+        }
         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 (revs->graph) {
+                html("</td><td>");
+                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();
+        }
+
         if (ctx.repo->enable_log_filecount) {
                 files = 0;
                 add_lines = 0;
@@ -110,29 +192,61 @@ void print_commit(struct commit *commit)
                 }
         }
         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++;
+        if (revs->graph || ctx.qry.showmsg) { /* Print a second table row */
+                html("<tr class='nohover'>");
+
+                if (ctx.qry.showmsg) {
+                        /* Concatenate commit message + notes in msgbuf */
+                        if (info->msg && *(info->msg)) {
+                                strbuf_addstr(&msgbuf, info->msg);
+                                strbuf_addch(&msgbuf, '\n');
+                        }
+                        format_note(NULL, commit->object.sha1, &msgbuf,
+                                    PAGE_ENCODING,
+                                    NOTES_SHOW_HEADER | NOTES_INDENT);
+                        strbuf_addch(&msgbuf, '\n');
+                        strbuf_ltrim(&msgbuf);
                 }
-                htmlf("<tr class='nohover'><td/><td colspan='%d' class='logmsg'>",
-                        cols);
-                html_txt(info->msg);
-                html("</td></tr>\n");
-                if (notes.len != 0) {
-                        html("<tr class='nohover'>");
-                        html("<td class='lognotes-label'>Notes:</td>");
-                        htmlf("<td colspan='%d' class='lognotes'>",
-                                cols);
-                        html_txt(notes.buf);
-                        html("</td></tr>\n");
+
+                if (revs->graph) {
+                        int lines = 0;
+
+                        /* Calculate graph padding */
+                        if (ctx.qry.showmsg) {
+                                /* Count #lines in commit message + notes */
+                                const char *p = msgbuf.buf;
+                                lines = 1;
+                                while ((p = strchr(p, '\n'))) {
+                                        p++;
+                                        lines++;
+                                }
+                        }
+
+                        /* Print graph padding */
+                        html("<td class='commitgraph'>");
+                        while (lines > 0 || !graph_is_commit_finished(revs->graph)) {
+                                if (graphbuf.len)
+                                        html("\n");
+                                strbuf_setlen(&graphbuf, 0);
+                                graph_next_line(revs->graph, &graphbuf);
+                                html(graphbuf.buf);
+                                lines--;
+                        }
+                        html("</td>\n");
                 }
-                strbuf_release(&notes);
+                else
+                        html("<td/>"); /* Empty 'Age' column */
+
+                /* Print msgbuf into remainder of table row */
+                htmlf("<td colspan='%d'%s>\n", cols,
+                        ctx.qry.showmsg ? " class='logmsg'" : "");
+                html_txt(msgbuf.buf);
+                html("</td></tr>\n");
         }
+
+        strbuf_release(&msgbuf);
+        strbuf_release(&graphbuf);
         cgit_free_commitinfo(info);
 }
 
@@ -148,38 +262,94 @@ static const char *disambiguate_ref(const char *ref)
         return ref;
 }
 
+static char *next_token(char **src)
+{
+        char *result;
+
+        if (!src || !*src)
+                return NULL;
+        while (isspace(**src))
+                (*src)++;
+        if (!**src)
+                return NULL;
+        result = *src;
+        while (**src) {
+                if (isspace(**src)) {
+                        **src = '\0';
+                        (*src)++;
+                        break;
+                }
+                (*src)++;
+        }
+        return result;
+}
+
 void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern,
-                    char *path, int pager)
+                    char *path, int pager, int commit_graph)
 {
         struct rev_info rev;
         struct commit *commit;
-        const char *argv[] = {NULL, NULL, NULL, NULL, NULL};
-        int argc = 2;
+        struct vector vec = VECTOR_INIT(char *);
         int i, columns = 3;
+        char *arg;
+
+        /* First argv is NULL */
+        vector_push(&vec, NULL, 0);
 
         if (!tip)
                 tip = ctx.qry.head;
-
-        argv[1] = disambiguate_ref(tip);
+        tip = disambiguate_ref(tip);
+        vector_push(&vec, &tip, 0);
 
         if (grep && pattern && *pattern) {
+                pattern = xstrdup(pattern);
                 if (!strcmp(grep, "grep") || !strcmp(grep, "author") ||
-                    !strcmp(grep, "committer"))
-                        argv[argc++] = fmt("--%s=%s", grep, pattern);
-                if (!strcmp(grep, "range"))
-                        argv[1] = pattern;
+                    !strcmp(grep, "committer")) {
+                        arg = fmt("--%s=%s", grep, pattern);
+                        vector_push(&vec, &arg, 0);
+                }
+                if (!strcmp(grep, "range")) {
+                        /* Split the pattern at whitespace and add each token
+                         * as a revision expression. Do not accept other
+                         * rev-list options. Also, replace the previously
+                         * pushed tip (it's no longer relevant).
+                         */
+                        vec.count--;
+                        while ((arg = next_token(&pattern))) {
+                                if (*arg == '-') {
+                                        fprintf(stderr, "Bad range expr: %s\n",
+                                                arg);
+                                        break;
+                                }
+                                vector_push(&vec, &arg, 0);
+                        }
+                }
+        }
+        if (commit_graph) {
+                static const char *graph_arg = "--graph";
+                static const char *color_arg = "--color";
+                vector_push(&vec, &graph_arg, 0);
+                vector_push(&vec, &color_arg, 0);
+                graph_set_column_colors(column_colors_html,
+                                        COLUMN_COLORS_HTML_MAX);
         }
 
         if (path) {
-                argv[argc++] = "--";
-                argv[argc++] = path;
+                arg = "--";
+                vector_push(&vec, &arg, 0);
+                vector_push(&vec, &path, 0);
         }
+
+        /* Make sure the vector is NULL-terminated */
+        vector_push(&vec, NULL, 0);
+        vec.count--;
+
         init_revisions(&rev, NULL);
         rev.abbrev = DEFAULT_ABBREV;
         rev.commit_format = CMIT_FMT_DEFAULT;
         rev.verbose_header = 1;
         rev.show_root_diff = 0;
-        setup_revisions(argc, argv, &rev, NULL);
+        setup_revisions(vec.count, vec.data, &rev, NULL);
         load_ref_decorations(DECORATE_FULL_REFS);
         rev.show_decorations = 1;
         rev.grep_filter.regflags |= REG_ICASE;
@@ -189,8 +359,12 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
         if (pager)
                 html("<table class='list nowrap'>");
 
-        html("<tr class='nohover'><th class='left'>Age</th>"
-              "<th class='left'>Commit message");
+        html("<tr class='nohover'>");
+        if (commit_graph)
+                html("<th></th>");
+        else
+                html("<th class='left'>Age</th>");
+        html("<th class='left'>Commit message");
         if (pager) {
                 html(" (");
                 cgit_log_link(ctx.qry.showmsg ? "Collapse" : "Expand", NULL,
@@ -200,6 +374,8 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
                 html(")");
         }
         html("</th><th class='left'>Author</th>");
+        if (commit_graph)
+                html("<th class='left'>Age</th>");
         if (ctx.repo->enable_log_filecount) {
                 html("<th class='left'>Files</th>");
                 columns++;
@@ -221,7 +397,7 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
         }
 
         for (i = 0; i < cnt && (commit = get_revision(&rev)) != NULL; i++) {
-                print_commit(commit);
+                print_commit(commit, &rev);
                 free(commit->buffer);
                 commit->buffer = NULL;
                 free_commit_list(commit->parents);
diff --git a/ui-log.h b/ui-log.h
index 6034055..d0cb779 100644
--- a/ui-log.h
+++ b/ui-log.h
@@ -2,7 +2,8 @@
 #define UI_LOG_H
 
 extern void cgit_print_log(const char *tip, int ofs, int cnt, char *grep,
-                           char *pattern, char *path, int pager);
+                           char *pattern, char *path, int pager,
+                           int commit_graph);
 extern void show_commit_decorations(struct commit *commit);
 
 #endif /* UI_LOG_H */
diff --git a/ui-summary.c b/ui-summary.c
index b203bcc..5be2545 100644
--- a/ui-summary.c
+++ b/ui-summary.c
@@ -59,7 +59,7 @@ void cgit_print_summary()
         if (ctx.cfg.summary_log > 0) {
                 html("<tr class='nohover'><td colspan='4'>&nbsp;</td></tr>");
                 cgit_print_log(ctx.qry.head, 0, ctx.cfg.summary_log, NULL,
-                               NULL, NULL, 0);
+                               NULL, NULL, 0, 0);
         }
         if (ctx.repo->clone_url)
                 print_urls(ctx.repo->clone_url, NULL);
diff --git a/vector.c b/vector.c
new file mode 100644
index 0000000..0863908
--- /dev/null
+++ b/vector.c
@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include "vector.h"
+
+static int grow(struct vector *vec, int gently)
+{
+        size_t new_alloc;
+        void *new_data;
+
+        new_alloc = vec->alloc * 3 / 2;
+        if (!new_alloc)
+                new_alloc = 8;
+        new_data = realloc(vec->data, new_alloc * vec->size);
+        if (!new_data) {
+                if (gently)
+                        return ENOMEM;
+                perror("vector.c:grow()");
+                exit(1);
+        }
+        vec->data = new_data;
+        vec->alloc = new_alloc;
+        return 0;
+}
+
+int vector_push(struct vector *vec, const void *data, int gently)
+{
+        int rc;
+
+        if (vec->count == vec->alloc && (rc = grow(vec, gently)))
+                return rc;
+        if (data)
+                memmove(vec->data + vec->count * vec->size, data, vec->size);
+        else
+                memset(vec->data + vec->count * vec->size, 0, vec->size);
+        vec->count++;
+        return 0;
+}
diff --git a/vector.h b/vector.h
new file mode 100644
index 0000000..c64eb1f
--- /dev/null
+++ b/vector.h
@@ -0,0 +1,17 @@
+#ifndef CGIT_VECTOR_H
+#define CGIT_VECTOR_H
+
+#include <stdlib.h>
+
+struct vector {
+        size_t size;
+        size_t count;
+        size_t alloc;
+        void *data;
+};
+
+#define VECTOR_INIT(type) {sizeof(type), 0, 0, NULL}
+
+int vector_push(struct vector *vec, const void *data, int gently);
+
+#endif /* CGIT_VECTOR_H */