From 6b6ff53b5931c162be13504a1efc53fc5212f9d1 Mon Sep 17 00:00:00 2001
From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Date: Mon, 7 May 2018 22:57:34 +0200
Subject: [PATCH] m4/reorganization/libs/curl.m4: fix curl-config detection
 logic

The current logic in curl.m4 doesn't behave properly when
--without-libcurl is passed to the ./configure script.

Indeed, in this case what happens is that:

 (1) Since --without-libcurl is passed, LIBCURL_HOME is set to nothing

 (2) find_curl is set to "no"

 (3) Due to find_curl being "no", LIBCURL_HOME is not set to
     /usr/local and remains empty

 (4) We test if $LIBCURL_HOME/bin/curl_config exists, which is
     equivalent to testing if /bin/curl-config exists. So curl.m4 is
     looking at /bin/curl-config, which is irrelevant in a
     cross-compilation context: it is not because the build machine
     has libcurl installed that it is available for the target.

     Due to this mistake, it sets have_curl="yes"

Due to this, the ./configure script assumes it can build the
clamsubmit program, which fails at build time because curl/curl.h
doesn't exist.

To fix this, this commit rewrites the curl-config detection logic with
a simpler loop. If find_curl=yes, it means we have to find libcurl
ourselves, so we iterate over /usr/local and /usr, and check if a
bin/curl-config binary is available there. If so, we use this path as
LIBCURL_HOME and set have_curl="yes".

This preserves the existing behavior, while fixing the situation where
--without-libcurl is passed, but /bin/curl-config exists.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Upstream-status: https://github.com/Cisco-Talos/clamav-devel/pull/87
---
 m4/reorganization/libs/curl.m4 | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/m4/reorganization/libs/curl.m4 b/m4/reorganization/libs/curl.m4
index 2a5966ee7..b6a9c2137 100644
--- a/m4/reorganization/libs/curl.m4
+++ b/m4/reorganization/libs/curl.m4
@@ -19,17 +19,12 @@ fi
 [find_curl="yes"])
 
 if test "X$find_curl" = "Xyes"; then
-    LIBCURL_HOME=/usr/local
-fi
-if test -f "$LIBCURL_HOME/bin/curl-config"; then
-    have_curl="yes"
-else
-    if test "X$find_curl" = "Xyes"; then
-        LIBCURL_HOME=/usr
-        if test -f "$LIBCURL_HOME/bin/curl-config"; then
-            have_curl="yes"
+    for p in /usr/local /usr ; do
+        if test -f "${p}/bin/curl-config"; then
+           LIBCURL_HOME=$p
+           have_curl="yes"
         fi
-    fi
+    done
 fi
 
 if test "X$have_curl" = "Xyes"; then
-- 
2.14.3