lib: remove strlen call from Curl_client_write

At all call sites with an explicit 0 len, pass an appropriate nonzero
len.

Closes #6954

4 files changed, 19 insertions, 15 deletions

diff --git a/lib/file.c b/lib/file.c
index 1d174e519..e54406699 100644
--- a/lib/file.c
+++ b/lib/file.c
@@ -410,16 +410,18 @@ static CURLcode file_do(struct Curl_easy *data, bool *done)
     struct tm buffer;
     const struct tm *tm = &buffer;
     char header[80];
+    int headerlen;
+    char accept_ranges[24]= { "Accept-ranges: bytes\r\n" };
     if(expected_size >= 0) {
-      msnprintf(header, sizeof(header),
+      headerlen = msnprintf(header, sizeof(header),
                 "Content-Length: %" CURL_FORMAT_CURL_OFF_T "\r\n",
                 expected_size);
-      result = Curl_client_write(data, CLIENTWRITE_HEADER, header, 0);
+      result = Curl_client_write(data, CLIENTWRITE_HEADER, header, headerlen);
       if(result)
         return result;
 
       result = Curl_client_write(data, CLIENTWRITE_HEADER,
-                                 (char *)"Accept-ranges: bytes\r\n", 0);
+                                 accept_ranges, strlen(accept_ranges));
       if(result != CURLE_OK)
         return result;
     }
@@ -430,7 +432,7 @@ static CURLcode file_do(struct Curl_easy *data, bool *done)
       return result;
 
     /* format: "Tue, 15 Nov 1994 12:45:26 GMT" */
-    msnprintf(header, sizeof(header),
+    headerlen = msnprintf(header, sizeof(header),
               "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n%s",
               Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
               tm->tm_mday,
@@ -440,7 +442,7 @@ static CURLcode file_do(struct Curl_easy *data, bool *done)
               tm->tm_min,
               tm->tm_sec,
               data->set.opt_no_body ? "": "\r\n");
-    result = Curl_client_write(data, CLIENTWRITE_HEADER, header, 0);
+    result = Curl_client_write(data, CLIENTWRITE_HEADER, header, headerlen);
     if(result)
       return result;
     /* set the file size to make it available post transfer */
diff --git a/lib/ftp.c b/lib/ftp.c
index 18d3c5ab0..463ddd5b2 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -2098,6 +2098,7 @@ static CURLcode ftp_state_mdtm_resp(struct Curl_easy *data,
          data->set.get_filetime &&
          (data->info.filetime >= 0) ) {
         char headerbuf[128];
+        int headerbuflen;
         time_t filetime = data->info.filetime;
         struct tm buffer;
         const struct tm *tm = &buffer;
@@ -2107,7 +2108,7 @@ static CURLcode ftp_state_mdtm_resp(struct Curl_easy *data,
           return result;
 
         /* format: "Tue, 15 Nov 1994 12:45:26" */
-        msnprintf(headerbuf, sizeof(headerbuf),
+        headerbuflen = msnprintf(headerbuf, sizeof(headerbuf),
                   "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
                   Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
                   tm->tm_mday,
@@ -2116,7 +2117,8 @@ static CURLcode ftp_state_mdtm_resp(struct Curl_easy *data,
                   tm->tm_hour,
                   tm->tm_min,
                   tm->tm_sec);
-        result = Curl_client_write(data, CLIENTWRITE_BOTH, headerbuf, 0);
+        result = Curl_client_write(data, CLIENTWRITE_BOTH, headerbuf,
+                                   headerbuflen);
         if(result)
           return result;
       } /* end of a ridiculous amount of conditionals */
@@ -2321,9 +2323,9 @@ static CURLcode ftp_state_size_resp(struct Curl_easy *data,
 #ifdef CURL_FTP_HTTPSTYLE_HEAD
     if(-1 != filesize) {
       char clbuf[128];
-      msnprintf(clbuf, sizeof(clbuf),
+      int clbuflen = msnprintf(clbuf, sizeof(clbuf),
                 "Content-Length: %" CURL_FORMAT_CURL_OFF_T "\r\n", filesize);
-      result = Curl_client_write(data, CLIENTWRITE_BOTH, clbuf, 0);
+      result = Curl_client_write(data, CLIENTWRITE_BOTH, clbuf, clbuflen);
       if(result)
         return result;
     }
@@ -2357,7 +2359,8 @@ static CURLcode ftp_state_rest_resp(struct Curl_easy *data,
 #ifdef CURL_FTP_HTTPSTYLE_HEAD
     if(ftpcode == 350) {
       char buffer[24]= { "Accept-ranges: bytes\r\n" };
-      result = Curl_client_write(data, CLIENTWRITE_BOTH, buffer, 0);
+      result = Curl_client_write(data, CLIENTWRITE_BOTH, buffer,
+                                 strlen(buffer));
       if(result)
         return result;
     }
diff --git a/lib/openldap.c b/lib/openldap.c
index 88bbb64a1..a5560fc9b 100644
--- a/lib/openldap.c
+++ b/lib/openldap.c
@@ -666,7 +666,7 @@ static ssize_t ldap_recv(struct Curl_easy *data, int sockindex, char *buf,
 
           data->req.bytecount += bvals[i].bv_len + 1;
         }
-        writeerr = Curl_client_write(data, CLIENTWRITE_BODY, (char *)"\n", 0);
+        writeerr = Curl_client_write(data, CLIENTWRITE_BODY, (char *)"\n", 1);
         if(writeerr) {
           *err = writeerr;
           return -1;
@@ -675,14 +675,14 @@ static ssize_t ldap_recv(struct Curl_easy *data, int sockindex, char *buf,
         data->req.bytecount++;
       }
       ber_memfree(bvals);
-      writeerr = Curl_client_write(data, CLIENTWRITE_BODY, (char *)"\n", 0);
+      writeerr = Curl_client_write(data, CLIENTWRITE_BODY, (char *)"\n", 1);
       if(writeerr) {
         *err = writeerr;
         return -1;
       }
       data->req.bytecount++;
     }
-    writeerr = Curl_client_write(data, CLIENTWRITE_BODY, (char *)"\n", 0);
+    writeerr = Curl_client_write(data, CLIENTWRITE_BODY, (char *)"\n", 1);
     if(writeerr) {
       *err = writeerr;
       return -1;
diff --git a/lib/sendf.c b/lib/sendf.c
index 8f6784c67..17d3d51e3 100644
--- a/lib/sendf.c
+++ b/lib/sendf.c
@@ -616,9 +616,8 @@ CURLcode Curl_client_write(struct Curl_easy *data,
                            size_t len)
 {
   struct connectdata *conn = data->conn;
-  if(0 == len)
-    len = strlen(ptr);
 
+  DEBUGASSERT(len);
   DEBUGASSERT(type <= 3);
 
   /* FTP data may need conversion. */