[gnumeric] solver: use better error messages when missing solver executables.

[Morten Welinder <mortenw src gnome org>]

commit 48ab60b5bde0327a4368732b01a13767b0d4b747
Author: Morten Welinder <terra gnome org>
Date:   Tue Dec 1 13:37:01 2009 -0500

    solver: use better error messages when missing solver executables.

 plugins/glpk/gnm-glpk.c       |   12 ++++++++++++
 plugins/lpsolve/gnm-lpsolve.c |   12 ++++++++++++
 2 files changed, 24 insertions(+), 0 deletions(-)
---
diff --git a/plugins/glpk/gnm-glpk.c b/plugins/glpk/gnm-glpk.c
index 04f7437..56b0bdb 100644
--- a/plugins/glpk/gnm-glpk.c
+++ b/plugins/glpk/gnm-glpk.c
@@ -15,6 +15,7 @@
 #include <unistd.h>
 
 #define SOLVER_PROGRAM "glpsol"
+#define SOLVER_URL "http://www.gnu.org/software/glpk/";
 #define PRIVATE_KEY "::glpk::"
 
 typedef struct {
@@ -277,6 +278,17 @@ gnm_glpk_start (GnmSolver *sol, WorkbookControl *wbc, GError **err,
 				   NULL, NULL,
 				   err);
 
+	if (!ok && err &&
+	    g_error_matches (*err, G_SPAWN_ERROR, G_SPAWN_ERROR_NOENT)) {
+		g_clear_error (err);
+		g_set_error (err, G_SPAWN_ERROR, G_SPAWN_ERROR_NOENT,
+			     _("The %s program was not found.  You can either "
+			       "install it or use another solver. "
+			       "For more information see %s"),
+			     SOLVER_PROGRAM,
+			     SOLVER_URL);
+	}
+
 	return ok;
 }
 
diff --git a/plugins/lpsolve/gnm-lpsolve.c b/plugins/lpsolve/gnm-lpsolve.c
index 9926ad0..4d89630 100644
--- a/plugins/lpsolve/gnm-lpsolve.c
+++ b/plugins/lpsolve/gnm-lpsolve.c
@@ -10,6 +10,7 @@
 #include <string.h>
 
 #define SOLVER_PROGRAM "lp_solve"
+#define SOLVER_URL "http://sourceforge.net/projects/lpsolve/";
 #define PRIVATE_KEY "::lpsolve::"
 
 typedef struct {
@@ -272,6 +273,17 @@ gnm_lpsolve_start (GnmSolver *sol, WorkbookControl *wbc, GError **err,
 				   NULL, NULL,
 				   err);
 
+	if (!ok && err &&
+	    g_error_matches (*err, G_SPAWN_ERROR, G_SPAWN_ERROR_NOENT)) {
+		g_clear_error (err);
+		g_set_error (err, G_SPAWN_ERROR, G_SPAWN_ERROR_NOENT,
+			     _("The %s program was not found.  You can either "
+			       "install it or use another solver. "
+			       "For more information see %s"),
+			     SOLVER_PROGRAM,
+			     SOLVER_URL);
+	}
+
 	return ok;
 }