From 4e59dc0b5eeb6cac3ffc9c26e85cccd9a5c61a59 Mon Sep 17 00:00:00 2001
From: dankelley <kelley.dan@gmail.com>
Date: Wed, 18 Dec 2019 13:20:56 -0400
Subject: [PATCH] improve two error messages:

1. for read.oce() on an empty file
2. for plot,echosounder-method() on an unrecognized 'which' value
---
 R/echosounder.R | 17 +++++++++--------
 R/oce.R         |  4 +++-
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/R/echosounder.R b/R/echosounder.R
index 7718fbb54c..d018b65a6c 100644
--- a/R/echosounder.R
+++ b/R/echosounder.R
@@ -578,16 +578,10 @@ setMethod(f="plot",
                   else
                       lay <- layout(matrix(1:2, nrow=2, byrow=TRUE))
               }
-              oceDebug(debug, "which:", which, "\n")
+              oceDebug(debug, "which before converting to numbers: c(", paste(which, collapse=","), ")\n")
               whichOrig <- which
               which <- oce.pmatch(which, list("zt image"=1, "zx image"=2, map=3))
-              if (!(which %in% 1:3)) {
-                  if (is.character(whichOrig))
-                      stop("In plot,echosounder-method : unknown value of which (\"", whichOrig, "\"); try 1, 2 or 3, or, equivalently, \"zt image\", \"zx image\" or \"map\"", call.=FALSE)
-                  else
-                      stop("In plot,echosounder-method : unknown value of which (", whichOrig, "); try 1, 2 or 3, or, equivalently, \"zt image\", \"zx image\" or \"map\"", call.=FALSE)
-              }
-              oceDebug(debug, "which:", which, "\n")
+              oceDebug(debug, "which after converting to numbers: c(", paste(which, collapse=","), ")\n")
               for (w in seq_along(which)) {
                   oceDebug(debug, "this which:", which[w], "\n")
                   if (which[w] == 1) {
@@ -757,6 +751,13 @@ setMethod(f="plot",
                           }
                       }
                       lines(lon, lat, col=if (!is.function(col)) col else "black", lwd=lwd)
+                  } else {
+                      stop("In plot,echosounder-method : unknown value of which (",
+                           if (is.character(whichOrig[w])) {
+                               paste("\"", whichOrig[w], "\"", sep="")
+                           }  else {
+                               whichOrig[w]
+                           }, "); try 1, 2 or 3, or, equivalently, \"zt image\", \"zx image\" or \"map\"", call.=FALSE)
                   }
               }
               oceDebug(debug, "} # plot.echosounder()\n", unindent=1, style="bold")
diff --git a/R/oce.R b/R/oce.R
index 0909a6d472..0f16004970 100644
--- a/R/oce.R
+++ b/R/oce.R
@@ -2024,8 +2024,10 @@ read.oce <- function(file, ...)
 {
     if (missing(file))
         stop("must supply 'file'")
+    if (is.character(file) && "http://" != substr(file, 1, 7) && !file.exists(file))
+        stop("In read.oce() : cannot open '", file, "' because there is no such file or directory", call.=FALSE)
     if (is.character(file) && "http://" != substr(file, 1, 7) && 0 == file.info(file)$size)
-        stop("empty file (read.oce)")
+        stop("empty file")
     dots <- list(...)
     debug <- if ("debug" %in% names(dots)) dots$debug else 0
     type <- oceMagic(file, debug=debug-1)