程序忽略了一行输入

Question

以下是我用来从用户输入创建结构的一些代码：

    // make a new branch from user input
branch usr_input_branch() {
  char main_text[INPUT_MAX_SIZE];
  char b1[INPUT_MAX_SIZE];
  char b2[INPUT_MAX_SIZE];
  char response[4];

  do {
    printf("Enter main text: ");
    fgets(main_text,INPUT_MAX_SIZE,stdin);
    if ((strlen(main_text)>0) && (main_text[strlen (main_text) - 1] == '\n'))
        main_text[strlen (main_text) - 1] = '\0';

    printf("Enter Option 1: ");
    fgets(b1,INPUT_MAX_SIZE,stdin);
    if ((strlen(b1)>0) && (b1[strlen (name) - 1] == '\n'))
        name[strlen (name) - 1] = '\0';

    printf("Enter Option 2: ");
    fgets(b2,INPUT_MAX_SIZE,stdin);
    if ((strlen(name)>0) && (name[strlen (name) - 1] == '\n'))
        name[strlen (name) - 1] = '\0';

    puts("Here is your branch:");

    branch br = brCreate(b1,b2,main_text);
    brPrint(br);

    printf("Is this OK? [Y/n] ");
    scanf("%s",response);
    int doLoop = 1;
    do {
      if (tolower(response[0]) == 'y')
      {
        return br;
      }
      else if (tolower(response[0]) == 'n') {
        doLoop = 0;
      }
      else {
        puts("Invalid response.");
        printf("Is this OK? [Y/n] ");
    scanf("%s",response);
      }
    } while (doLoop);
  } while (1);

  // inaccessible code
  error("Inaccessible code",0);
  return brCreate("","","");
}

这是我想要的输出：

Enter main text: stuff1
Enter Option 1: stuff2
Enter Option 2: stuff3

Here is your branch:
stuff1
Option 1: stuff2
Option 2: stuff3

然而：这是发生的事情：

Enter main text: Enter Option 1: stuff
Enter Option 2: stuff1
Here is your branch:


Option 1: stuff

Option 2: stuff1

它似乎完全忽略了第一件事，并直接转向第二件事。我应该怎么做才能解决这个问题？

我正在使用gcc和c99以防万一。