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 */