strerror: Preserve Windows error code in some functions

This is a follow-up to af02162 which removed (SET_)ERRNO macros. That
commit was an earlier draft that I committed by mistake, which was then
remedied by a5834e5 and e909de6, and now this commit. With this commit
there is now no difference between the current code and the changes that
were approved in the final draft.

Thanks-to: Max Dymond, Marcel Raad, Daniel Stenberg, Gisle Vanem
Ref: https://github.com/curl/curl/pull/1589

diff --git a/lib/strerror.c b/lib/strerror.c
index a85c216a51994714f0b62f13d56cce68110d273f..83a96dda195ef3ecb520bea6eade20e8f1eb2828 100644 (file)
--- a/lib/strerror.c
+++ b/lib/strerror.c
@@ -49,6 +49,10 @@
 #include "curl_memory.h"
 #include "memdebug.h"
 
+#if defined(WIN32) || defined(_WIN32_WCE)
+#define PRESERVE_WINDOWS_ERROR_CODE
+#endif
+
 const char *
 curl_easy_strerror(CURLcode error)
 {
@@ -432,6 +436,10 @@ curl_share_strerror(CURLSHcode error)
 static const char *
 get_winsock_error (int err, char *buf, size_t len)
 {
+#ifdef PRESERVE_WINDOWS_ERROR_CODE
+  DWORD old_win_err = GetLastError();
+#endif
+  int old_errno = errno;
   const char *p;
 
 #ifndef CURL_DISABLE_VERBOSE_STRINGS
@@ -611,6 +619,15 @@ get_winsock_error (int err, char *buf, size_t len)
 #endif
   strncpy(buf, p, len);
   buf [len-1] = '\0';
+
+  if(errno != old_errno)
+    errno = old_errno;
+
+#ifdef PRESERVE_WINDOWS_ERROR_CODE
+  if(old_win_err != GetLastError())
+    SetLastError(old_win_err);
+#endif
+
   return buf;
 }
 #endif   /* USE_WINSOCK */
@@ -628,19 +645,16 @@ get_winsock_error (int err, char *buf, size_t len)
  */
 const char *Curl_strerror(struct connectdata *conn, int err)
 {
+#ifdef PRESERVE_WINDOWS_ERROR_CODE
+  DWORD old_win_err = GetLastError();
+#endif
+  int old_errno = errno;
   char *buf, *p;
   size_t max;
-  int old_errno;
-#ifdef WIN32
-  DWORD old_win_err;
-#endif
+
   DEBUGASSERT(conn);
   DEBUGASSERT(err >= 0);
 
-  old_errno = errno;
-#ifdef WIN32
-  old_win_err = GetLastError();
-#endif
   buf = conn->syserr_buf;
   max = sizeof(conn->syserr_buf)-1;
   *buf = '\0';
@@ -727,12 +741,14 @@ const char *Curl_strerror(struct connectdata *conn, int err)
   p = strrchr(buf, '\r');
   if(p && (p - buf) >= 1)
     *p = '\0';
-#ifdef WIN32
+
+  if(errno != old_errno)
+    errno = old_errno;
+
+#ifdef PRESERVE_WINDOWS_ERROR_CODE
   if(old_win_err != GetLastError())
     SetLastError(old_win_err);
 #endif
-  if(errno != old_errno)
-    errno = old_errno;
 
   return buf;
 }
@@ -740,17 +756,19 @@ const char *Curl_strerror(struct connectdata *conn, int err)
 #ifdef USE_WINDOWS_SSPI
 const char *Curl_sspi_strerror (struct connectdata *conn, int err)
 {
+#ifdef PRESERVE_WINDOWS_ERROR_CODE
+  DWORD old_win_err = GetLastError();
+#endif
+  int old_errno = errno;
+  const char *txt;
+  char *outbuf;
+  size_t outmax;
 #ifndef CURL_DISABLE_VERBOSE_STRINGS
   char txtbuf[80];
   char msgbuf[sizeof(conn->syserr_buf)];
   char *p, *str, *msg = NULL;
   bool msg_formatted = FALSE;
-  int old_errno;
-  DWORD old_win_err;
 #endif
-  const char *txt;
-  char *outbuf;
-  size_t outmax;
 
   DEBUGASSERT(conn);
 
@@ -760,9 +778,6 @@ const char *Curl_sspi_strerror (struct connectdata *conn, int err)
 
 #ifndef CURL_DISABLE_VERBOSE_STRINGS
 
-  old_errno = errno;
-  old_win_err = GetLastError();
-
   switch(err) {
     case SEC_E_OK:
       txt = "No error";
@@ -1062,12 +1077,6 @@ const char *Curl_sspi_strerror (struct connectdata *conn, int err)
       strncpy(outbuf, str, outmax);
   }
 
-  if(old_win_err != GetLastError())
-    SetLastError(old_win_err);
-
-  if(errno != old_errno)
-    errno = old_errno;
-
 #else
 
   if(err == SEC_E_OK)
@@ -1081,6 +1090,14 @@ const char *Curl_sspi_strerror (struct connectdata *conn, int err)
 
   outbuf[outmax] = '\0';
 
+  if(errno != old_errno)
+    errno = old_errno;
+
+#ifdef PRESERVE_WINDOWS_ERROR_CODE
+  if(old_win_err != GetLastError())
+    SetLastError(old_win_err);
+#endif
+
   return outbuf;
 }
 #endif /* USE_WINDOWS_SSPI */

diff --git a/tests/libtest/lib505.c b/tests/libtest/lib505.c
index 0c128c6660c622e5546e230c106379337c1d7b51..ad5d214c69208085722e3b610f633e6e15f681a8 100644 (file)
--- a/tests/libtest/lib505.c
+++ b/tests/libtest/lib505.c
@@ -42,7 +42,6 @@ int test(char *URL)
   int hd;
   struct_stat file_info;
   struct curl_slist *hl;
-  int error;
 
   struct curl_slist *headerlist=NULL;
   const char *buf_1 = "RNFR 505";
@@ -55,9 +54,8 @@ int test(char *URL)
 
   hd_src = fopen(libtest_arg2, "rb");
   if(NULL == hd_src) {
-    error = errno;
     fprintf(stderr, "fopen failed with error: %d %s\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "Error opening file: %s\n", libtest_arg2);
     return TEST_ERR_MAJOR_BAD; /* if this happens things are major weird */
   }
@@ -66,9 +64,8 @@ int test(char *URL)
   hd = fstat(fileno(hd_src), &file_info);
   if(hd == -1) {
     /* can't open file, bail out */
-    error = errno;
     fprintf(stderr, "fstat() failed with error: %d %s\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "ERROR: cannot open file %s\n", libtest_arg2);
     fclose(hd_src);
     return TEST_ERR_MAJOR_BAD;

diff --git a/tests/libtest/lib525.c b/tests/libtest/lib525.c
index f468efa25c19ce50c3295a59602c2af4a4d5d341..715b7fbe2de12c96bc303c2ccbf8865cbdd5b8ca 100644 (file)
--- a/tests/libtest/lib525.c
+++ b/tests/libtest/lib525.c
@@ -35,7 +35,6 @@ int test(char *URL)
   CURL *curl = NULL;
   FILE *hd_src = NULL;
   int hd;
-  int error;
   struct_stat file_info;
   CURLM *m = NULL;
   int running;
@@ -55,9 +54,8 @@ int test(char *URL)
 
   hd_src = fopen(libtest_arg2, "rb");
   if(NULL == hd_src) {
-    error = errno;
     fprintf(stderr, "fopen failed with error: %d (%s)\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "Error opening file: (%s)\n", libtest_arg2);
     return TEST_ERR_FOPEN;
   }
@@ -66,9 +64,8 @@ int test(char *URL)
   hd = fstat(fileno(hd_src), &file_info);
   if(hd == -1) {
     /* can't open file, bail out */
-    error = errno;
     fprintf(stderr, "fstat() failed with error: %d (%s)\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "ERROR: cannot open file (%s)\n", libtest_arg2);
     fclose(hd_src);
     return TEST_ERR_FSTAT;

diff --git a/tests/libtest/lib541.c b/tests/libtest/lib541.c
index 9aa4a082603920351610127be5d04aaeb3a699bd..94a26a4b7f7343cd9b7f1acf7180727f67610ccd 100644 (file)
--- a/tests/libtest/lib541.c
+++ b/tests/libtest/lib541.c
@@ -38,7 +38,6 @@ int test(char *URL)
   FILE *hd_src;
   int hd;
   struct_stat file_info;
-  int error;
 
   if(!libtest_arg2) {
     fprintf(stderr, "Usage: <url> <file-to-upload>\n");
@@ -47,9 +46,8 @@ int test(char *URL)
 
   hd_src = fopen(libtest_arg2, "rb");
   if(NULL == hd_src) {
-    error = errno;
     fprintf(stderr, "fopen failed with error: %d %s\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "Error opening file: %s\n", libtest_arg2);
     return -2; /* if this happens things are major weird */
   }
@@ -58,9 +56,8 @@ int test(char *URL)
   hd = fstat(fileno(hd_src), &file_info);
   if(hd == -1) {
     /* can't open file, bail out */
-    error = errno;
     fprintf(stderr, "fstat() failed with error: %d %s\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "ERROR: cannot open file %s\n", libtest_arg2);
     fclose(hd_src);
     return TEST_ERR_MAJOR_BAD;

diff --git a/tests/libtest/lib582.c b/tests/libtest/lib582.c
index 23772be59e75230ffea39935e842f119de99191e..f55e5de71214d54a29ab1aba80974d87598424b8 100644 (file)
--- a/tests/libtest/lib582.c
+++ b/tests/libtest/lib582.c
@@ -228,7 +228,6 @@ int test(char *URL)
   CURL *curl = NULL;
   FILE *hd_src = NULL;
   int hd;
-  int error;
   struct_stat file_info;
   CURLM *m = NULL;
   struct ReadWriteSockets sockets = {{NULL, 0, 0}, {NULL, 0, 0}};
@@ -244,9 +243,8 @@ int test(char *URL)
 
   hd_src = fopen(libtest_arg2, "rb");
   if(NULL == hd_src) {
-    error = errno;
     fprintf(stderr, "fopen() failed with error: %d (%s)\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "Error opening file: (%s)\n", libtest_arg2);
     return TEST_ERR_FOPEN;
   }
@@ -255,9 +253,8 @@ int test(char *URL)
   hd = fstat(fileno(hd_src), &file_info);
   if(hd == -1) {
     /* can't open file, bail out */
-    error = errno;
     fprintf(stderr, "fstat() failed with error: %d (%s)\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "ERROR: cannot open file (%s)\n", libtest_arg2);
     fclose(hd_src);
     return TEST_ERR_FSTAT;

diff --git a/tests/libtest/lib591.c b/tests/libtest/lib591.c
index c04d3fbaed7df6c5a43f97c8b5ceb29527960dc4..53ede3fcd31d93fe5069f567e09f7122bf705ba6 100644 (file)
--- a/tests/libtest/lib591.c
+++ b/tests/libtest/lib591.c
@@ -44,15 +44,13 @@ int test(char *URL)
   int msgs_left;
   CURLMsg *msg;
   FILE *upload = NULL;
-  int error;
 
   start_test_timing();
 
   upload = fopen(libtest_arg3, "rb");
   if(!upload) {
-    error = errno;
     fprintf(stderr, "fopen() failed with error: %d (%s)\n",
-            error, strerror(error));
+            errno, strerror(errno));
     fprintf(stderr, "Error opening file: (%s)\n", libtest_arg3);
     return TEST_ERR_FOPEN;
   }