Implement safe_strncpy() as strlcpy() and use it more.

Signed-off-by: Peter Eriksen <s022018@student.dtu.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-log.c

@@ -112,7 +112,7 @@ static void reopen_stdout(struct commit *commit, int nr, int keep_subject)
 	int len = 0;
 
 	if (output_directory) {
-		strncpy(filename, output_directory, 1010);
+		safe_strncpy(filename, output_directory, 1010);
 		len = strlen(filename);
 		if (filename[len - 1] != '/')
 			filename[len++] = '/';

builtin-tar-tree.c

@@ -240,8 +240,8 @@ static void write_entry(const unsigned char *sha1, struct strbuf *path,
 	/* XXX: should we provide more meaningful info here? */
 	sprintf(header.uid, "%07o", 0);
 	sprintf(header.gid, "%07o", 0);
-	strncpy(header.uname, "git", 31);
+	safe_strncpy(header.uname, "git", sizeof(header.uname));
-	strncpy(header.gname, "git", 31);
+	safe_strncpy(header.gname, "git", sizeof(header.gname));
 	sprintf(header.devmajor, "%07o", 0);
 	sprintf(header.devminor, "%07o", 0);
 

cache.h

@@ -210,7 +210,7 @@ int git_mkstemp(char *path, size_t n, const char *template);
 
 int adjust_shared_perm(const char *path);
 int safe_create_leading_directories(char *path);
-char *safe_strncpy(char *, const char *, size_t);
+size_t safe_strncpy(char *, const char *, size_t);
 char *enter_repo(char *path, int strict);
 
 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */

config.c

@@ -280,17 +280,17 @@ int git_default_config(const char *var, const char *value)
 	}
 
 	if (!strcmp(var, "user.name")) {
-		strncpy(git_default_name, value, sizeof(git_default_name));
+		safe_strncpy(git_default_name, value, sizeof(git_default_name));
 		return 0;
 	}
 
 	if (!strcmp(var, "user.email")) {
-		strncpy(git_default_email, value, sizeof(git_default_email));
+		safe_strncpy(git_default_email, value, sizeof(git_default_email));
 		return 0;
 	}
 
 	if (!strcmp(var, "i18n.commitencoding")) {
-		strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
+		safe_strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
 		return 0;
 	}
 

http-fetch.c

@@ -584,10 +584,8 @@ static void process_alternates_response(void *callback_data)
 			// skip 'objects' at end
 			if (okay) {
 				target = xmalloc(serverlen + posn - i - 6);
-				strncpy(target, base, serverlen);
+				safe_strncpy(target, base, serverlen);
-				strncpy(target + serverlen, data + i,
+				safe_strncpy(target + serverlen, data + i, posn - i - 6);
-					posn - i - 7);
-				target[serverlen + posn - i - 7] = '\0';
 				if (get_verbosely)
 					fprintf(stderr,
 						"Also look at %s\n", target);
@@ -728,8 +726,8 @@ xml_cdata(void *userData, const XML_Char *s, int len)
 	struct xml_ctx *ctx = (struct xml_ctx *)userData;
 	if (ctx->cdata)
 		free(ctx->cdata);
-	ctx->cdata = xcalloc(len+1, 1);
+	ctx->cdata = xmalloc(len + 1);
-	strncpy(ctx->cdata, s, len);
+	safe_strncpy(ctx->cdata, s, len + 1);
 }
 
 static int remote_ls(struct alt_base *repo, const char *path, int flags,

http-push.c

@@ -1269,8 +1269,8 @@ xml_cdata(void *userData, const XML_Char *s, int len)
 	struct xml_ctx *ctx = (struct xml_ctx *)userData;
 	if (ctx->cdata)
 		free(ctx->cdata);
-	ctx->cdata = xcalloc(len+1, 1);
+	ctx->cdata = xmalloc(len + 1);
-	strncpy(ctx->cdata, s, len);
+	safe_strncpy(ctx->cdata, s, len + 1);
 }
 
 static struct remote_lock *lock_remote(char *path, long timeout)
@@ -1472,7 +1472,7 @@ static void process_ls_object(struct remote_ls_ctx *ls)
 		return;
 	path += 8;
 	obj_hex = xmalloc(strlen(path));
-	strncpy(obj_hex, path, 2);
+	safe_strncpy(obj_hex, path, 3);
 	strcpy(obj_hex + 2, path + 3);
 	one_remote_object(obj_hex);
 	free(obj_hex);
@@ -2160,8 +2160,8 @@ static void fetch_symref(char *path, char **symref, unsigned char *sha1)
 
 	/* If it's a symref, set the refname; otherwise try for a sha1 */
 	if (!strncmp((char *)buffer.buffer, "ref: ", 5)) {
-		*symref = xcalloc(buffer.posn - 5, 1);
+		*symref = xmalloc(buffer.posn - 5);
-		strncpy(*symref, (char *)buffer.buffer + 5, buffer.posn - 6);
+		safe_strncpy(*symref, (char *)buffer.buffer + 5, buffer.posn - 5);
 	} else {
 		get_sha1_hex(buffer.buffer, sha1);
 	}

ident.c

@@ -71,10 +71,9 @@ int setup_ident(void)
 		len = strlen(git_default_email);
 		git_default_email[len++] = '.';
 		if (he && (domainname = strchr(he->h_name, '.')))
-			strncpy(git_default_email + len, domainname + 1, sizeof(git_default_email) - len);
+			safe_strncpy(git_default_email + len, domainname + 1, sizeof(git_default_email) - len);
 		else
-			strncpy(git_default_email + len, "(none)", sizeof(git_default_email) - len);
+			safe_strncpy(git_default_email + len, "(none)", sizeof(git_default_email) - len);
-		git_default_email[sizeof(git_default_email) - 1] = 0;
 	}
 	/* And set the default date */
 	datestamp(git_default_date, sizeof(git_default_date));

path.c

@@ -83,13 +83,18 @@ int git_mkstemp(char *path, size_t len, const char *template)
 }
 
 
-char *safe_strncpy(char *dest, const char *src, size_t n)
+size_t safe_strncpy(char *dest, const char *src, size_t size)
 {
-	strncpy(dest, src, n);
+	size_t ret = strlen(src);
-	dest[n - 1] = '\0';
 
-	return dest;
+	if (size) {
+		size_t len = (ret >= size) ? size - 1 : ret;
+		memcpy(dest, src, len);
+		dest[len] = '\0';
 	}
+	return ret;
+}
+
 
 int validate_symref(const char *path)
 {

sha1_name.c

@@ -262,8 +262,7 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 		if (str[am] == '@' && str[am+1] == '{' && str[len-1] == '}') {
 			int date_len = len - am - 3;
 			char *date_spec = xmalloc(date_len + 1);
-			strncpy(date_spec, str + am + 2, date_len);
+			safe_strncpy(date_spec, str + am + 2, date_len + 1);
-			date_spec[date_len] = 0;
 			at_time = approxidate(date_spec);
 			free(date_spec);
 			len = am;