Windows: Add workaround for MSYS' path conversion

MSYS' automatic path conversion causes problems when passing paths as
defines ('-D' arguments to the compiler).  MSYS tries to be smart and
converts absolute paths to native Windows paths, e.g. if MSYS sees
"/bin" it converts it to "c:/msysgit/bin".  But we want completely
unmodified paths; e.g. if we set bindir in the Makefile to "/bin", the
define BINDIR shall expand to "/bin".  Conversion to absolute Windows
path will takes place later, during runtime.

This commit adds a workaround by replacing "/" with its octal
representation "\057", effectively hiding the path from MSYS' path
conversion mechanism.  MSYS does no longer see the absolute path and
therefore leaves it alone.

Author: sprohaska

Makefile

@@ -1049,6 +1049,12 @@ template_dir_SQ = $(subst ','\'',$(template_dir))
 htmldir_SQ = $(subst ','\'',$(htmldir))
 prefix_SQ = $(subst ','\'',$(prefix))
 
+ETC_GITCONFIG_SQ_C = $(subst /,\057,$(ETC_GITCONFIG_SQ))
+bindir_SQ_C = $(subst /,\057,$(bindir_SQ))
+gitexecdir_SQ_C = $(subst /,\057,$(gitexecdir_SQ))
+htmldir_SQ_C = $(subst /,\057,$(htmldir_SQ))
+template_dir_SQ_C = $(subst /,\057,$(template_dir_SQ))
+
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
 TCLTK_PATH_SQ = $(subst ','\'',$(TCLTK_PATH))
@@ -1100,7 +1106,7 @@ git$X: git.o $(BUILTIN_OBJS) $(GITLIBS)
 
 help.o: help.c common-cmds.h GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) \
-		'-DGIT_HTML_PATH="$(htmldir_SQ)"' \
+		'-DGIT_HTML_PATH="$(htmldir_SQ_C)"' \
 		'-DGIT_MAN_PATH="$(mandir_SQ)"' \
 		'-DGIT_INFO_PATH="$(infodir_SQ)"' $<
 
@@ -1207,12 +1213,12 @@ git.o git.spec \
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 
 exec_cmd.o: exec_cmd.c GIT-CFLAGS
-	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) '-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' $<
+	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) '-DGIT_EXEC_PATH="$(gitexecdir_SQ_C)"' -DBINDIR='"$(bindir_SQ_C)"' $<
 builtin-init-db.o: builtin-init-db.c GIT-CFLAGS
-	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DDEFAULT_GIT_TEMPLATE_DIR='"$(template_dir_SQ)"' $<
+	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DDEFAULT_GIT_TEMPLATE_DIR='"$(template_dir_SQ_C)"' $<
 
 config.o: config.c GIT-CFLAGS
-	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DETC_GITCONFIG='"$(ETC_GITCONFIG_SQ)"' $<
+	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DETC_GITCONFIG='"$(ETC_GITCONFIG_SQ_C)"' $<
 
 http.o: http.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DGIT_USER_AGENT='"git/$(GIT_VERSION)"' $<