Correctly detect truncated input in header parsing

If the section header is the last line in the file,
parse_section_header would incorrectly decide that the input had been
truncated.

Fix this by checking whether the actual input line is correctly
formatted.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

src/config_file.c

@@ -721,11 +721,6 @@ static int parse_section_header(diskfile_backend *cfg, char **section_out)
 	c = line[pos++];
 
 	do {
-		if (cfg->reader.eof){
-			error = git__throw(GIT_EOBJCORRUPTED, "Failed to parse header. Config file ended unexpectedly");
-			goto error;
-		}
-
 		if (isspace(c)){
 			name[name_length] = '\0';
 			error = parse_section_header_ext(line, name, section_out);
@@ -743,6 +738,9 @@ static int parse_section_header(diskfile_backend *cfg, char **section_out)
 
 	} while ((c = line[pos++]) != ']');
 
+	if (line[pos - 1] != ']')
+		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse header. Config file ended unexpectedly");
+
 	name[name_length] = 0;
 	free(line);
 	git__strtolower(name);