foo.c: In function 'Concat':
foo.c:9:9: warning: 'strncpy' specified bound depends on the length of the source argument [-Wstringop-truncation]
    9 |         strncpy(result, str1, len1 - 1);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:5:16: note: length computed here
    5 |     int len1 = strlen(str1);
      |                ^~~~~~~~~~~~

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