pause: handle mixed types of data when paused

When receiving chunked encoded data with trailers, and the write
callback returns PAUSE, there might be both body and header to store to
resend on unpause. Previously libcurl returned error for that case.

Added test case 1540 to verify.

Reported-by: Stephen Toub
Fixes #1354
Closes #1357

1 files changed, 53 insertions, 34 deletions

diff --git a/lib/sendf.c b/lib/sendf.c
index e03241f0d..84b6b4b2f 100644
--- a/lib/sendf.c
+++ b/lib/sendf.c
@@ -33,6 +33,7 @@
 #include "non-ascii.h"
 #include "strerror.h"
 #include "select.h"
+#include "strdup.h"
 
 /* The last 3 #include files should be in this order */
 #include "curl_printf.h"
@@ -474,21 +475,58 @@ static CURLcode pausewrite(struct Curl_easy *data,
      we want to send we need to dup it to save a copy for when the sending
      is again enabled */
   struct SingleRequest *k = &data->req;
-  char *dupl = malloc(len);
-  if(!dupl)
-    return CURLE_OUT_OF_MEMORY;
+  struct UrlState *s = &data->state;
+  char *dupl;
+  unsigned int i;
+  bool newtype = TRUE;
+
+  if(s->tempcount) {
+    for(i=0; i< s->tempcount; i++) {
+      if(s->tempwrite[i].type == type) {
+        /* data for this type exists */
+        newtype = FALSE;
+        break;
+      }
+    }
+    DEBUGASSERT(i < 3);
+  }
+  else
+    i = 0;
+
+  if(!newtype) {
+    /* append new data to old data */
+
+    /* figure out the new size of the data to save */
+    size_t newlen = len + s->tempwrite[i].len;
+    /* allocate the new memory area */
+    char *newptr = realloc(s->tempwrite[i].buf, newlen);
+    if(!newptr)
+      return CURLE_OUT_OF_MEMORY;
+    /* copy the new data to the end of the new area */
+    memcpy(newptr + s->tempwrite[i].len, ptr, len);
+
+    /* update the pointer and the size */
+    s->tempwrite[i].buf = newptr;
+    s->tempwrite[i].len = newlen;
+  }
+  else {
+    dupl = Curl_memdup(ptr, len);
+    if(!dupl)
+      return CURLE_OUT_OF_MEMORY;
 
-  memcpy(dupl, ptr, len);
+    /* store this information in the state struct for later use */
+    s->tempwrite[i].buf = dupl;
+    s->tempwrite[i].len = len;
+    s->tempwrite[i].type = type;
 
-  /* store this information in the state struct for later use */
-  data->state.tempwrite = dupl;
-  data->state.tempwritesize = len;
-  data->state.tempwritetype = type;
+    if(newtype)
+      s->tempcount++;
+  }
 
   /* mark the connection as RECV paused */
   k->keepon |= KEEP_RECV_PAUSE;
 
-  DEBUGF(infof(data, "Pausing with %zu bytes in buffer for type %02x\n",
+  DEBUGF(infof(data, "Paused %zu bytes in buffer for type %02x\n",
                len, type));
 
   return CURLE_OK;
@@ -511,31 +549,10 @@ CURLcode Curl_client_chop_write(struct connectdata *conn,
   if(!len)
     return CURLE_OK;
 
-  /* If reading is actually paused, we're forced to append this chunk of data
-     to the already held data, but only if it is the same type as otherwise it
-     can't work and it'll return error instead. */
-  if(data->req.keepon & KEEP_RECV_PAUSE) {
-    size_t newlen;
-    char *newptr;
-    if(type != data->state.tempwritetype)
-      /* major internal confusion */
-      return CURLE_RECV_ERROR;
-
-    DEBUGASSERT(data->state.tempwrite);
-
-    /* figure out the new size of the data to save */
-    newlen = len + data->state.tempwritesize;
-    /* allocate the new memory area */
-    newptr = realloc(data->state.tempwrite, newlen);
-    if(!newptr)
-      return CURLE_OUT_OF_MEMORY;
-    /* copy the new data to the end of the new area */
-    memcpy(newptr + data->state.tempwritesize, ptr, len);
-    /* update the pointer and the size */
-    data->state.tempwrite = newptr;
-    data->state.tempwritesize = newlen;
-    return CURLE_OK;
-  }
+  /* If reading is paused, append this data to the already held data for this
+     type. */
+  if(data->req.keepon & KEEP_RECV_PAUSE)
+    return pausewrite(data, type, ptr, len);
 
   /* Determine the callback(s) to use. */
   if(type & CLIENTWRITE_BODY)
@@ -615,6 +632,8 @@ CURLcode Curl_client_write(struct connectdata *conn,
   if(0 == len)
     len = strlen(ptr);
 
+  DEBUGASSERT(type <= 3);
+
   /* FTP data may need conversion. */
   if((type & CLIENTWRITE_BODY) &&
     (conn->handler->protocol & PROTO_FAMILY_FTP) &&