Amplify the comment on renderLogMsg() that explains the problems associated

with calling sqlite3_log() from deep within the memory allocator.

FossilOrigin-Name: a73d7128fbca8dde5e90bd46ee915e39ae07dd1f

src/printf.c

@@ -1012,6 +1012,11 @@ char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
 ** allocate memory because it might be called while the memory allocator
 ** mutex is held.
+**
+** sqlite3VXPrintf() might ask for *temporary* memory allocations for
+** certain format characters (%q) or for very large precisions or widths.
+** Care must be taken that any sqlite3_log() calls that occur while the
+** memory mutex is held do not use these mechanisms.
 */
 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
   StrAccum acc;                          /* String accumulator */