tab: Drop redundant assertions.

[pspp] / configure.ac

diff --git a/configure.ac b/configure.ac
index 4d6cab7c2229b656041ae4668db9d9bf83402391..8f4ca63ba084f9c4e6341bf409caa1a4be5d8f94 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -145,6 +145,18 @@ AC_CHECK_HEADERS(
   [HAVE_ZLIB=no
    PSPP_OPTIONAL_PREREQ([zlib])])
 
+dnl Avoid interference between zlib's crc32() function and gnulib's
+dnl crc32() function, which have different signatures.  PSPP calls
+dnl only gnulib's crc32() directly, but it calls zlib's crc32()
+dnl indirectly through other zlib calls.  If we don't rename gnulib's
+dnl crc32(), then zlib will call gnulib's version instead of its own,
+dnl causing failures.  (This can happen even if zlib isn't detected
+dnl directly, because other libraries that PSPP uses, e.g. libpng,
+dnl sometimes use zlib themselves.)
+AC_DEFINE(
+  [crc32], [gl_crc32],
+  [Avoid making zlib call gnulib's crc32() instead of its own.])
+
 dnl Gnumeric support requires libxml2 and zlib.
 if test $HAVE_LIBXML2 = yes && test $HAVE_ZLIB = yes; then
   GNM_SUPPORT=yes