Potential usage of an uninitialized variable - Rebuild of the Debian archive with clang

"Potential usage of an uninitialized variable" build failure(s) — clang 3.8.1

int f(int b) {
  int n;
  if (b)
    n = 1;
  return n;
}

In some cases, n can be uninitialized.
gcc -Werror plop.c will accept this code while clang -Werror plop.c will fail.

Package	Version	Supposed error message	Full log	Bug report
altermime	0.3.10-8	mime_alter.c:709:13: error: variable 'newblock' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]	Log	~~753058~~
u1db	13.10-6.2	u1db_query.c:902:9: error: variable 'statement' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]	Log
vzquota	3.1-1	quotaon.c:1002:7: error: variable 'ugid' is used uninitialized whenever '\|\|' condition is true [-Werror,-Wsometimes-uninitialized]	Log	~~753065~~

3 errors