[gimp] INSTALL, configure: add Dr. MinGW information...

[Jehan Pagès <jehanp src gnome org>]

commit 24334f3e5941c76fa6f6ac44e7543c7c4d516842
Author: Jehan <jehan girinstud io>
Date:   Sat Jun 11 23:33:26 2016 +0200

    INSTALL, configure: add Dr. MinGW information...
    
    ... in the INSTALL file, but also in the summary of optional
    dependencies at the end of the configure script.

 INSTALL.in   |   19 +++++++++++++------
 configure.ac |   10 ++++++++--
 2 files changed, 21 insertions(+), 8 deletions(-)
---
diff --git a/INSTALL.in b/INSTALL.in
index ef4bbde..e5cb97a 100644
--- a/INSTALL.in
+++ b/INSTALL.in
@@ -103,19 +103,25 @@ header files installed.
      or newer) to be present. You will also need PyGTK and the
      respective development headers.
 
- 13. Configure GIMP by running the `configure' script. You may want
+ 13. Windows builds can now generate backtrace logs upon a crash.
+     The logs will be available in: %APPDATA%\GIMP\ GIMP_APP_VERSION@\CrashLog\
+     The feature depends on Dr.MinGW's ExcHndl library:
+
+        https://github.com/jrfonseca/drmingw
+
+ 14. Configure GIMP by running the `configure' script. You may want
      to pass some options to it, see below.
 
- 14. Build GIMP by running `make'. The use of GNU make is recommended.
+ 15. Build GIMP by running `make'. The use of GNU make is recommended.
      If you need to tweak the build to make it work with other flavours
      of make, we'd appreciate if you'd send us a patch with the changes.
 
- 15. Install GIMP by running `make install'. In order to avoid clashes
+ 16. Install GIMP by running `make install'. In order to avoid clashes
      with other versions of GIMP, we install a binary called gimp- GIMP_APP_VERSION@.
      By default there's also a link created so that you can type 'gimp'
      to start gimp- GIMP_APP_VERSION@.
 
- 16. Summary of required packages and what version you need:
+ 17. Summary of required packages and what version you need:
 
      Package Name      Version
 
@@ -140,7 +146,7 @@ header files installed.
      pangocairo        @PANGOCAIRO_REQUIRED_VERSION@
      zlib
 
- 17. Summary of optional packages:
+ 18. Summary of optional packages:
 
      Package Name      Version         Feature
 
@@ -158,8 +164,9 @@ header files installed.
      libwmf            @WMF_REQUIRED_VERSION@          WMF
      libXcursor                -               X11 Mouse Cursor
      libxpm            -               XPM
+     ExcHndl           -               Crash logs on Windows with Dr. MinGW
 
- 18. Summary of optional runtime dependencies:
+ 19. Summary of optional runtime dependencies:
 
      darktable >= 1.7, with lua support enabled for raw loading
      xdg-email for sending emails
diff --git a/configure.ac b/configure.ac
index ef3f666..e3cfc88 100644
--- a/configure.ac
+++ b/configure.ac
@@ -813,11 +813,16 @@ PKG_CHECK_MODULES(GEXIV2, gexiv2 >= gexiv2_required_version,,
 # Check for Dr. Mingw
 #####################
 
+enable_drmingw="no"
 if test "x$platform_win32" = "xyes"; then
    # Check for Dr. Mingw
    AC_CHECK_LIB(exchndl, ExcHndlSetLogFileNameA,
-               [AC_DEFINE(HAVE_EXCHNDL, 1, [Define to 1 when Dr. MingW is available])]
-               )
+                [
+                 AC_DEFINE(HAVE_EXCHNDL, 1, [Define to 1 when Dr. MingW is available])
+                 enable_drmingw="yes"
+                ],
+                [enable_drmingw="no (ExcHndl library missing)"]
+               )
 fi
 AM_CONDITIONAL(HAVE_EXCHNDL, test "x$ac_cv_lib_exchndl_ExcHndlSetLogFileNameA" = "xyes")
 
@@ -2517,6 +2522,7 @@ Extra Binaries:
 Optional Features:
   Language selection:  $have_iso_codes
   Vectorial icons:     $enable_vector_icons
+  Dr. Mingw (Win32):   $enable_drmingw
 
 Optional Plug-Ins:
   Ascii Art:           $have_libaa