curl_setup: Add macros for FOPEN_READTEXT, FOPEN_WRITETEXT

- Change fopen calls to use FOPEN_READTEXT instead of "r" or "rt"
- Change fopen calls to use FOPEN_WRITETEXT instead of "w" or "wt"

This change is to explicitly specify when we need to read/write text.
Unfortunately 't' is not part of POSIX fopen so we can't specify it
directly. Instead we now have FOPEN_READTEXT, FOPEN_WRITETEXT.

Prior to this change we had an issue on Windows if an application that
uses libcurl overrides the default file mode to binary. The default file
mode in Windows is normally text mode (translation mode) and that's what
libcurl expects.

Bug: https://github.com/bagder/curl/pull/258#issuecomment-107093055
Reported-by: Orgad Shaneh

6 files changed, 26 insertions, 10 deletions

diff --git a/lib/cookie.c b/lib/cookie.c
index 012792605..fd7ed4168 100644
--- a/lib/cookie.c
+++ b/lib/cookie.c
@@ -914,7 +914,7 @@ struct CookieInfo *Curl_cookie_init(struct SessionHandle *data,
     fp = NULL;
   }
   else
-    fp = file?fopen(file, "r"):NULL;
+    fp = file?fopen(file, FOPEN_READTEXT):NULL;
 
   c->newsession = newsession; /* new session? */
 
@@ -1262,7 +1262,7 @@ static int cookie_output(struct CookieInfo *c, const char *dumphere)
     use_stdout=TRUE;
   }
   else {
-    out = fopen(dumphere, "w");
+    out = fopen(dumphere, FOPEN_WRITETEXT);
     if(!out)
       return 1; /* failure */
   }
diff --git a/lib/curl_setup.h b/lib/curl_setup.h
index 9c7cc07eb..cbec34f26 100644
--- a/lib/curl_setup.h
+++ b/lib/curl_setup.h
@@ -707,4 +707,24 @@ int netware_init(void);
 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
 #endif
 
+/* In Windows the default file mode is text but an application can override it.
+Therefore we specify it explicitly. https://github.com/bagder/curl/pull/258
+*/
+#if defined(WIN32)
+#define FOPEN_READTEXT "rt"
+#define FOPEN_WRITETEXT "wt"
+#elif defined(__CYGWIN__)
+/* Cygwin has specific behavior we need to address when WIN32 is not defined.
+https://cygwin.com/cygwin-ug-net/using-textbinary.html
+For write we want our output to have line endings of LF and be compatible with
+other Cygwin utilities. For read we want to handle input that may have line
+endings either CRLF or LF so 't' is appropriate.
+*/
+#define FOPEN_READTEXT "rt"
+#define FOPEN_WRITETEXT "w"
+#else
+#define FOPEN_READTEXT "r"
+#define FOPEN_WRITETEXT "w"
+#endif
+
 #endif /* HEADER_CURL_SETUP_H */
diff --git a/lib/memdebug.c b/lib/memdebug.c
index 3b38a7492..dd8889b2d 100644
--- a/lib/memdebug.c
+++ b/lib/memdebug.c
@@ -112,7 +112,7 @@ void curl_memdebug(const char *logname)
 {
   if(!logfile) {
     if(logname && *logname)
-      logfile = fopen(logname, "w");
+      logfile = fopen(logname, FOPEN_WRITETEXT);
     else
       logfile = stderr;
 #ifdef MEMDEBUG_LOG_SYNC
diff --git a/lib/netrc.c b/lib/netrc.c
index 97a07b88e..06f8ea15a 100644
--- a/lib/netrc.c
+++ b/lib/netrc.c
@@ -109,11 +109,7 @@ int Curl_parsenetrc(const char *host,
     netrc_alloc = TRUE;
   }
 
-#ifdef __CYGWIN__
-  file = fopen(netrcfile, "rt");
-#else
-  file = fopen(netrcfile, "r");
-#endif
+  file = fopen(netrcfile, FOPEN_READTEXT);
   if(netrc_alloc)
     free(netrcfile);
   if(file) {
diff --git a/lib/vtls/gtls.c b/lib/vtls/gtls.c
index d6eb6c445..1db31e40c 100644
--- a/lib/vtls/gtls.c
+++ b/lib/vtls/gtls.c
@@ -231,7 +231,7 @@ static gnutls_datum_t load_file (const char *file)
   long filelen;
   void *ptr;
 
-  if(!(f = fopen(file, "r")))
+  if(!(f = fopen(file, "rb")))
     return loaded_file;
   if(fseek(f, 0, SEEK_END) != 0
      || (filelen = ftell(f)) < 0
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 96a7d6e89..eb2cf5bf5 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -2725,7 +2725,7 @@ static CURLcode servercert(struct connectdata *conn,
 
     /* e.g. match issuer name with provided issuer certificate */
     if(data->set.str[STRING_SSL_ISSUERCERT]) {
-      fp = fopen(data->set.str[STRING_SSL_ISSUERCERT], "r");
+      fp = fopen(data->set.str[STRING_SSL_ISSUERCERT], FOPEN_READTEXT);
       if(!fp) {
         if(strict)
           failf(data, "SSL: Unable to open issuer cert (%s)",