BUG/MINOR: pattern: handle errors from fgets when trying to load patterns

We need to do some error handling after we call fgets to make sure everything
went fine. If we don't users can be fooled into thinking they can load pattens
from directory because cfgparse doesn't flinch. This applies to acl patterns
map files.

This should be backported to all supported versions.

(cherry picked from commit 3c79d4bdc47e151a97d7acdd99382bd9ca3927a5)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit bfa549da979e13f6c6a2e2defb7bbda5efa908f5)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/pattern.c b/src/pattern.c
index ec7e955..33e0e17 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -2328,6 +2328,11 @@
 		}
 	}
 
+	if (ferror(file)) {
+		memprintf(err, "error encountered while reading  <%s> : %s",
+				filename, strerror(errno));
+		goto out_close;
+	}
 	/* succes */
 	ret = 1;
 
@@ -2385,6 +2390,11 @@
 		}
 	}
 
+	if (ferror(file)) {
+		memprintf(err, "error encountered while reading  <%s> : %s",
+				filename, strerror(errno));
+		goto out_close;
+	}
 	ret = 1; /* success */
 
  out_close: