In pipe_read_line Windows code, loop to ensure we get a whole line

from the child process; fixes observed problems when the returned
version number is '8.0.0' rather than '8.0.0rc1'.  Magnus Hagander

diff --git a/src/port/exec.c b/src/port/exec.c
index 19ab92a07253c641756858e1ec303bb1f879b8ce..62a833cb8520669a74b5a96b51e47491c1d6a870 100644 (file)
--- a/src/port/exec.c
+++ b/src/port/exec.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/port/exec.c,v 1.33 2004/11/27 22:44:15 petere Exp $
+ *       $PostgreSQL: pgsql/src/port/exec.c,v 1.34 2004/12/20 17:40:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -486,30 +486,45 @@ pipe_read_line(char *cmd, char *line, int maxsize)
                                          &si,
                                          &pi))
        {
-               DWORD           bytesread = 0;
-
                /* Successfully started the process */
+               char   *lineptr;
 
                ZeroMemory(line, maxsize);
 
-               /* Let's see if we can read */
-               if (WaitForSingleObject(childstdoutrddup, 10000) != WAIT_OBJECT_0)
+               /* Try to read at least one line from the pipe */
+               /* This may require more than one wait/read attempt */
+               for (lineptr = line; lineptr < line+maxsize-1; )
                {
-                       /* Got timeout */
-                       CloseHandle(pi.hProcess);
-                       CloseHandle(pi.hThread);
-                       CloseHandle(childstdoutwr);
-                       CloseHandle(childstdoutrddup);
-                       return NULL;
+                       DWORD           bytesread = 0;
+
+                       /* Let's see if we can read */
+                       if (WaitForSingleObject(childstdoutrddup, 10000) != WAIT_OBJECT_0)
+                               break;          /* Timeout, but perhaps we got a line already */
+
+                       if (!ReadFile(childstdoutrddup, lineptr, maxsize-(lineptr-line),
+                                                 &bytesread, NULL))
+                               break;          /* Error, but perhaps we got a line already */
+
+                       lineptr += strlen(lineptr);
+
+                       if (!bytesread)
+                               break; /* EOF */
+
+                       if (strchr(line, '\n'))
+                               break; /* One or more lines read */
                }
 
-               /* We try just once */
-               if (ReadFile(childstdoutrddup, line, maxsize, &bytesread, NULL) &&
-                       bytesread > 0)
+               if (lineptr != line)
                {
-                       /* So we read some data */
-                       int                     len = strlen(line);
-                       retval = line;
+                       /* OK, we read some data */
+                       int                     len;
+
+                       /* If we got more than one line, cut off after the first \n */
+                       lineptr = strchr(line,'\n');
+                       if (lineptr)
+                               *(lineptr+1) = '\0';
+
+                       len = strlen(line);
 
                        /*
                         * If EOL is \r\n, convert to just \n. Because stdout is a
@@ -531,6 +546,8 @@ pipe_read_line(char *cmd, char *line, int maxsize)
                         */
                        if (len == 0 || line[len - 1] != '\n')
                                strcat(line, "\n");
+
+                       retval = line;
                }
 
                CloseHandle(pi.hProcess);