shared.c: avoid memory leak during diff

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/shared.c b/shared.c
index 9362d21..6adf2b6 100644
--- a/shared.c
+++ b/shared.c
@@ -89,336 +89,344 @@ void *cgit_free_commitinfo(struct commitinfo *info)
 	free(info->committer);
 	free(info->committer_email);
 	free(info->subject);
 	free(info->msg);
 	free(info->msg_encoding);
 	free(info);
 	return NULL;
 }
 
 char *trim_end(const char *str, char c)
 {
 	int len;
 	char *s, *t;
 
 	if (str == NULL)
 		return NULL;
 	t = (char *)str;
 	len = strlen(t);
 	while(len > 0 && t[len - 1] == c)
 		len--;
 
 	if (len == 0)
 		return NULL;
 
 	c = t[len];
 	t[len] = '\0';
 	s = xstrdup(t);
 	t[len] = c;
 	return s;
 }
 
 char *strlpart(char *txt, int maxlen)
 {
 	char *result;
 
 	if (!txt)
 		return txt;
 
 	if (strlen(txt) <= maxlen)
 		return txt;
 	result = xmalloc(maxlen + 1);
 	memcpy(result, txt, maxlen - 3);
 	result[maxlen-1] = result[maxlen-2] = result[maxlen-3] = '.';
 	result[maxlen] = '\0';
 	return result;
 }
 
 char *strrpart(char *txt, int maxlen)
 {
 	char *result;
 
 	if (!txt)
 		return txt;
 
 	if (strlen(txt) <= maxlen)
 		return txt;
 	result = xmalloc(maxlen + 1);
 	memcpy(result + 3, txt + strlen(txt) - maxlen + 4, maxlen - 3);
 	result[0] = result[1] = result[2] = '.';
 	return result;
 }
 
 void cgit_add_ref(struct reflist *list, struct refinfo *ref)
 {
 	size_t size;
 
 	if (list->count >= list->alloc) {
 		list->alloc += (list->alloc ? list->alloc : 4);
 		size = list->alloc * sizeof(struct refinfo *);
 		list->refs = xrealloc(list->refs, size);
 	}
 	list->refs[list->count++] = ref;
 }
 
 struct refinfo *cgit_mk_refinfo(const char *refname, const unsigned char *sha1)
 {
 	struct refinfo *ref;
 
 	ref = xmalloc(sizeof (struct refinfo));
 	ref->refname = xstrdup(refname);
 	ref->object = parse_object(sha1);
 	switch (ref->object->type) {
 	case OBJ_TAG:
 		ref->tag = cgit_parse_tag((struct tag *)ref->object);
 		break;
 	case OBJ_COMMIT:
 		ref->commit = cgit_parse_commit((struct commit *)ref->object);
 		break;
 	}
 	return ref;
 }
 
 int cgit_refs_cb(const char *refname, const unsigned char *sha1, int flags,
 		  void *cb_data)
 {
 	struct reflist *list = (struct reflist *)cb_data;
 	struct refinfo *info = cgit_mk_refinfo(refname, sha1);
 
 	if (info)
 		cgit_add_ref(list, info);
 	return 0;
 }
 
 void cgit_diff_tree_cb(struct diff_queue_struct *q,
 		       struct diff_options *options, void *data)
 {
 	int i;
 
 	for (i = 0; i < q->nr; i++) {
 		if (q->queue[i]->status == 'U')
 			continue;
 		((filepair_fn)data)(q->queue[i]);
 	}
 }
 
 static int load_mmfile(mmfile_t *file, const unsigned char *sha1)
 {
 	enum object_type type;
 
 	if (is_null_sha1(sha1)) {
 		file->ptr = (char *)"";
 		file->size = 0;
 	} else {
 		file->ptr = read_sha1_file(sha1, &type, 
 		                           (unsigned long *)&file->size);
 	}
 	return 1;
 }
 
 /*
  * Receive diff-buffers from xdiff and concatenate them as
  * needed across multiple callbacks.
  *
  * This is basically a copy of xdiff-interface.c/xdiff_outf(),
  * ripped from git and modified to use globals instead of
  * a special callback-struct.
  */
 char *diffbuf = NULL;
 int buflen = 0;
 
 int filediff_cb(void *priv, mmbuffer_t *mb, int nbuf)
 {
 	int i;
 
 	for (i = 0; i < nbuf; i++) {
 		if (mb[i].ptr[mb[i].size-1] != '\n') {
 			/* Incomplete line */
 			diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
 			memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
 			buflen += mb[i].size;
 			continue;
 		}
 
 		/* we have a complete line */
 		if (!diffbuf) {
 			((linediff_fn)priv)(mb[i].ptr, mb[i].size);
 			continue;
 		}
 		diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
 		memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
 		((linediff_fn)priv)(diffbuf, buflen + mb[i].size);
 		free(diffbuf);
 		diffbuf = NULL;
 		buflen = 0;
 	}
 	if (diffbuf) {
 		((linediff_fn)priv)(diffbuf, buflen);
 		free(diffbuf);
 		diffbuf = NULL;
 		buflen = 0;
 	}
 	return 0;
 }
 
 int cgit_diff_files(const unsigned char *old_sha1,
 		    const unsigned char *new_sha1, unsigned long *old_size,
 		    unsigned long *new_size, int *binary, linediff_fn fn)
 {
 	mmfile_t file1, file2;
 	xpparam_t diff_params;
 	xdemitconf_t emit_params;
 	xdemitcb_t emit_cb;
 
 	if (!load_mmfile(&file1, old_sha1) || !load_mmfile(&file2, new_sha1))
 		return 1;
 
 	*old_size = file1.size;
 	*new_size = file2.size;
 
 	if ((file1.ptr && buffer_is_binary(file1.ptr, file1.size)) ||
 	    (file2.ptr && buffer_is_binary(file2.ptr, file2.size))) {
 		*binary = 1;
+		if (file1.size)
+			free(file1.ptr);
+		if (file2.size)
+			free(file2.ptr);
 		return 0;
 	}
 
 	memset(&diff_params, 0, sizeof(diff_params));
 	memset(&emit_params, 0, sizeof(emit_params));
 	memset(&emit_cb, 0, sizeof(emit_cb));
 	diff_params.flags = XDF_NEED_MINIMAL;
 	emit_params.ctxlen = 3;
 	emit_params.flags = XDL_EMIT_FUNCNAMES;
 	emit_cb.outf = filediff_cb;
 	emit_cb.priv = fn;
 	xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
+	if (file1.size)
+		free(file1.ptr);
+	if (file2.size)
+		free(file2.ptr);
 	return 0;
 }
 
 void cgit_diff_tree(const unsigned char *old_sha1,
 		    const unsigned char *new_sha1,
 		    filepair_fn fn, const char *prefix)
 {
 	struct diff_options opt;
 	int ret;
 	int prefixlen;
 
 	diff_setup(&opt);
 	opt.output_format = DIFF_FORMAT_CALLBACK;
 	opt.detect_rename = 1;
 	opt.rename_limit = ctx.cfg.renamelimit;
 	DIFF_OPT_SET(&opt, RECURSIVE);
 	opt.format_callback = cgit_diff_tree_cb;
 	opt.format_callback_data = fn;
 	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)
 {
 	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);
 }
 
 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)
 			break;
 		for (f = cgit_snapshot_formats; f->suffix; f++) {
 			sl = strlen(f->suffix);
 			if((tl == sl && !strncmp(f->suffix, str, tl)) ||
 			   (tl == sl-1 && !strncmp(f->suffix+1, str, tl-1))) {
 				rv |= f->bit;
 				break;
 			}
 		}
 		str += tl;
 	}
 	return rv;
 }
 
 int cgit_open_filter(struct cgit_filter *filter)
 {
 
 	filter->old_stdout = chk_positive(dup(STDOUT_FILENO),
 		"Unable to duplicate STDOUT");
 	chk_zero(pipe(filter->pipe_fh), "Unable to create pipe to subprocess");
 	filter->pid = chk_non_negative(fork(), "Unable to create subprocess");
 	if (filter->pid == 0) {
 		close(filter->pipe_fh[1]);
 		chk_non_negative(dup2(filter->pipe_fh[0], STDIN_FILENO),
 			"Unable to use pipe as STDIN");
 		execvp(filter->cmd, filter->argv);
 		die("Unable to exec subprocess %s: %s (%d)", filter->cmd,
 			strerror(errno), errno);
 	}
 	close(filter->pipe_fh[0]);
 	chk_non_negative(dup2(filter->pipe_fh[1], STDOUT_FILENO),
 		"Unable to use pipe as STDOUT");
 	close(filter->pipe_fh[1]);
 	return 0;
 }
 
 int cgit_close_filter(struct cgit_filter *filter)
 {
 	chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
 		"Unable to restore STDOUT");
 	close(filter->old_stdout);
 	if (filter->pid < 0)
 		return 0;
 	waitpid(filter->pid, &filter->exitstatus, 0);
 	if (WIFEXITED(filter->exitstatus) && !WEXITSTATUS(filter->exitstatus))
 		return 0;
 	die("Subprocess %s exited abnormally", filter->cmd);
 }
 
 /* Read the content of the specified file into a newly allocated buffer,
  * zeroterminate the buffer and return 0 on success, errno otherwise.
  */
 int readfile(const char *path, char **buf, size_t *size)
 {
 	int fd, e;
 	struct stat st;
 
 	fd = open(path, O_RDONLY);
 	if (fd == -1)
 		return errno;
 	if (fstat(fd, &st)) {
 		e = errno;
 		close(fd);
 		return e;
 	}
 	if (!S_ISREG(st.st_mode)) {
 		close(fd);
 		return EISDIR;
 	}
 	*buf = xmalloc(st.st_size + 1);
 	*size = read_in_full(fd, *buf, st.st_size);
 	e = errno;
 	(*buf)[*size] = '\0';
 	close(fd);
 	return (*size == st.st_size ? 0 : e);
 }