From b1288964e31069bdf81abe560c82874f6f620928 Mon Sep 17 00:00:00 2001
From: adanhawth <36526095+adanhawth@users.noreply.github.com>
Date: Tue, 1 Feb 2022 21:38:15 -0500
Subject: bpo-46602: Do not append conftest.c (GH-31062)

The heredoc creation statements use >> to append conftest.c.  This can cause
tricky build issues if the file is not correctly removed prior to its
name being reused (such name is reused several times for different
contextual tests during the build).  One such result from appending may
cause #include <ac_nonexistent.h> to persist when testing to acquire
PLATFORM_TRIPLET.  This can then lead to downstream issues concerning SOABI.
---
 Misc/NEWS.d/next/Build/2022-02-02-02-06-07.bpo-46602.8GaOZ2.rst | 1 +
 configure                                                       | 4 ++--
 configure.ac                                                    | 4 ++--
 3 files changed, 5 insertions(+), 4 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Build/2022-02-02-02-06-07.bpo-46602.8GaOZ2.rst

diff --git a/Misc/NEWS.d/next/Build/2022-02-02-02-06-07.bpo-46602.8GaOZ2.rst b/Misc/NEWS.d/next/Build/2022-02-02-02-06-07.bpo-46602.8GaOZ2.rst
new file mode 100644
index 0000000..a1123b4
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2022-02-02-02-06-07.bpo-46602.8GaOZ2.rst
@@ -0,0 +1 @@
+Tidied up configure.ac so that conftest.c is truncated rather than appended.  This assists in the case where the 'rm' of conftest.c fails to happen between tests.  Downstream issues such as a clobbered SOABI can result.
\ No newline at end of file
diff --git a/configure b/configure
index 015b516..9097c05 100755
--- a/configure
+++ b/configure
@@ -5942,7 +5942,7 @@ fi
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for the platform triplet based on compiler characteristics" >&5
 $as_echo_n "checking for the platform triplet based on compiler characteristics... " >&6; }
-cat >> conftest.c <<EOF
+cat > conftest.c <<EOF
 #undef bfin
 #undef cris
 #undef fr30
@@ -6169,7 +6169,7 @@ $as_echo "$ac_cv_wl_no_as_needed" >&6; }
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for the Android API level" >&5
 $as_echo_n "checking for the Android API level... " >&6; }
-cat >> conftest.c <<EOF
+cat > conftest.c <<EOF
 #ifdef __ANDROID__
 android_api = __ANDROID_API__
 arm_arch = __ARM_ARCH
diff --git a/configure.ac b/configure.ac
index 6204747..b613c18 100644
--- a/configure.ac
+++ b/configure.ac
@@ -833,7 +833,7 @@ fi
 
 
 AC_MSG_CHECKING([for the platform triplet based on compiler characteristics])
-cat >> conftest.c <<EOF
+cat > conftest.c <<EOF
 #undef bfin
 #undef cris
 #undef fr30
@@ -1028,7 +1028,7 @@ AC_CACHE_CHECK([for -Wl,--no-as-needed], [ac_cv_wl_no_as_needed], [
 AC_SUBST(NO_AS_NEEDED)
 
 AC_MSG_CHECKING([for the Android API level])
-cat >> conftest.c <<EOF
+cat > conftest.c <<EOF
 #ifdef __ANDROID__
 android_api = __ANDROID_API__
 arm_arch = __ARM_ARCH
-- 
cgit v0.12