Makefile.m32: fix to not require OpenSSL with -libssh2 or -rtmp options

Previously, -libssh2/-rtmp options assumed that OpenSSL is also enabled
(and then failed with an error when not finding expected OpenSSL headers),
but this isn't necessarly true, e.g. when building both libssh2 and curl
against Schannel. This patch makes sure to only enable the OpenSSL backend
with -libssh2/-rtmp, when there was no SSL option explicitly selected.

- Re-implement the logic as a single block of script.
- Also fix an indentation while there.

Assisted-by: Jay Satiro

Closes #7895

docs/examples/Makefile.m32

@@ -178,12 +178,10 @@ ARES = 1
 endif
 ifeq ($(findstring -rtmp,$(CFG)),-rtmp)
 RTMP = 1
-SSL = 1
 ZLIB = 1
 endif
 ifeq ($(findstring -ssh2,$(CFG)),-ssh2)
 SSH2 = 1
-SSL = 1
 ZLIB = 1
 endif
 ifeq ($(findstring -ssl,$(CFG)),-ssl)
@@ -230,6 +228,13 @@ ifeq ($(findstring -ngtcp2,$(CFG)),-ngtcp2)
 NGTCP2 = 1
 endif
 
+# SSH2 and RTMP require an SSL library; assume OpenSSL if none specified
+ifneq ($(SSH2)$(RTMP),)
+  ifeq ($(SSL)$(WINSSL),)
+    SSL = 1
+  endif
+endif
+
 INCLUDES = -I. -I$(PROOT) -I$(PROOT)/include -I$(PROOT)/lib
 
 ifdef DYN
@@ -284,7 +289,7 @@ ifdef SSL
     endif
   endif
   ifneq "$(wildcard $(OPENSSL_INCLUDE)/openssl/opensslv.h)" "$(OPENSSL_INCLUDE)/openssl/opensslv.h"
-  $(error Invalid path to OpenSSL package: $(OPENSSL_PATH))
+    $(error Invalid path to OpenSSL package: $(OPENSSL_PATH))
   endif
   ifndef OPENSSL_LIBPATH
     OPENSSL_LIBS = -lssl -lcrypto

lib/Makefile.m32

@@ -179,12 +179,10 @@ SYNC = 1
 endif
 ifeq ($(findstring -rtmp,$(CFG)),-rtmp)
 RTMP = 1
-SSL = 1
 ZLIB = 1
 endif
 ifeq ($(findstring -ssh2,$(CFG)),-ssh2)
 SSH2 = 1
-SSL = 1
 ZLIB = 1
 endif
 ifeq ($(findstring -ssl,$(CFG)),-ssl)
@@ -237,6 +235,13 @@ ifeq ($(findstring -unicode,$(CFG)),-unicode)
 UNICODE = 1
 endif
 
+# SSH2 and RTMP require an SSL library; assume OpenSSL if none specified
+ifneq ($(SSH2)$(RTMP),)
+  ifeq ($(SSL)$(WINSSL),)
+    SSL = 1
+  endif
+endif
+
 INCLUDES = -I. -I../include
 CFLAGS += -DBUILDING_LIBCURL
 ifdef SSL
@@ -299,7 +304,7 @@ ifdef SSL
     endif
   endif
   ifneq "$(wildcard $(OPENSSL_INCLUDE)/openssl/opensslv.h)" "$(OPENSSL_INCLUDE)/openssl/opensslv.h"
-  $(error Invalid path to OpenSSL package: $(OPENSSL_PATH))
+    $(error Invalid path to OpenSSL package: $(OPENSSL_PATH))
   endif
   ifndef OPENSSL_LIBPATH
     ifeq "$(wildcard $(OPENSSL_PATH)/out)" "$(OPENSSL_PATH)/out"

src/Makefile.m32

@@ -187,12 +187,10 @@ SYNC = 1
 endif
 ifeq ($(findstring -rtmp,$(CFG)),-rtmp)
 RTMP = 1
-SSL = 1
 ZLIB = 1
 endif
 ifeq ($(findstring -ssh2,$(CFG)),-ssh2)
 SSH2 = 1
-SSL = 1
 ZLIB = 1
 endif
 ifeq ($(findstring -ssl,$(CFG)),-ssl)
@@ -242,6 +240,13 @@ ifeq ($(findstring -unicode,$(CFG)),-unicode)
 UNICODE = 1
 endif
 
+# SSH2 and RTMP require an SSL library; assume OpenSSL if none specified
+ifneq ($(SSH2)$(RTMP),)
+  ifeq ($(SSL)$(WINSSL),)
+    SSL = 1
+  endif
+endif
+
 INCLUDES = -I. -I../include -I../lib
 ifdef SSL
   ifdef WINSSL
@@ -309,7 +314,7 @@ ifdef SSL
     endif
   endif
   ifneq "$(wildcard $(OPENSSL_INCLUDE)/openssl/opensslv.h)" "$(OPENSSL_INCLUDE)/openssl/opensslv.h"
-  $(error Invalid path to OpenSSL package: $(OPENSSL_PATH))
+    $(error Invalid path to OpenSSL package: $(OPENSSL_PATH))
   endif
   ifndef OPENSSL_LIBPATH
     OPENSSL_LIBS = -lssl -lcrypto