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: curl#258 (comment)
Reported-by: Orgad Shaneh

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 */
   }

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 */

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

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) {

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

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)",

src/tool_cb_dbg.c

@@ -79,7 +79,7 @@ int tool_debug_cb(CURL *handle, curl_infotype type,
       /* Ok, this is somewhat hackish but we do it undocumented for now */
       config->trace_stream = config->errors;  /* aka stderr */
     else {
-      config->trace_stream = fopen(config->trace_dump, "w");
+      config->trace_stream = fopen(config->trace_dump, FOPEN_WRITETEXT);
       config->trace_fopened = TRUE;
     }
   }

src/tool_easysrc.c

@@ -176,7 +176,7 @@ void dumpeasysrc(struct GlobalConfig *config)
     FILE *out;
     bool fopened = FALSE;
     if(strcmp(o, "-")) {
-      out = fopen(o, "w");
+      out = fopen(o, FOPEN_WRITETEXT);
       fopened = TRUE;
     }
     else

src/tool_getparam.c

@@ -681,7 +681,7 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
 
       case 'v': /* --stderr */
         if(strcmp(nextarg, "-")) {
-          FILE *newfile = fopen(nextarg, "wt");
+          FILE *newfile = fopen(nextarg, FOPEN_WRITETEXT);
           if(!newfile)
             warnf(global, "Failed to open %s!\n", nextarg);
           else {
@@ -1748,7 +1748,7 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         }
         else {
           fname = nextarg;
-          file = fopen(nextarg, "r");
+          file = fopen(nextarg, FOPEN_READTEXT);
         }
         err = file2string(&config->writeout, file);
         if(file && (file != stdin))

src/tool_parsecfg.c

@@ -69,7 +69,7 @@ int parseconfig(const char *filename, struct GlobalConfig *global)
         /* Check if the file exists - if not, try CURLRC in the same
          * directory as our executable
          */
-        file = fopen(filebuffer, "r");
+        file = fopen(filebuffer, FOPEN_READTEXT);
         if(file != NULL) {
           fclose(file);
           filename = filebuffer;
@@ -115,7 +115,7 @@ int parseconfig(const char *filename, struct GlobalConfig *global)
   }
 
   if(strcmp(filename, "-"))
-    file = fopen(filename, "r");
+    file = fopen(filename, FOPEN_READTEXT);
   else
     file = stdin;